Caudipteryx and oviraptorosaurs
John Harshman
(Sorry about the line spacing, but I cut and pasted from Dejanews)
OK, I'll do the work for you. Here are the characters (from Sereno 1997
[typo: 1999]) that
make Caudipteryx an oviraptorosaur, as opposed to some other kind of theropod.
That is, these are the characters possessed by Caudipteryx that change
unambiguously (in all cases from 0 to 1) on the branch uniting Caudipteryx with
Oviraptoridae. Not all of them are unique to
oviraptorosaurs, but the combination of characters is unique. I do not
include the
characters that make all these taxa maniraptorans, tetanurans, coelurosaurs,
theropods, saurischians, or dinosaurs.
132. Antorbital fossa, form of ventral margin: rounded crest (0);
invaginated (1).
146. Chevron length: approximately twice (0), or 4-5 times (1),
corresponding neural spine height.
154. External naris, elevation of ventral margin: at the level of (0), or
dorsal to
(1), the maxilla.
155. Premaxilla participation in antorbital fossa: absent (0); present
(1). 156.
Mid-snout length: nasal longer (0), or shorter (1), than frontal. 157. Maxilla,
form of ramus along ventral margin of antorbital fossa: flat (0); inset
medially for
dentary and surangular of lower jaw.
158. Jugal orbital ramus, form of mid-section: transversely compressed (0);
rod-shaped (1).
159. Primary palate, position: mostly between (0), or ventral to (1),
maxilla and
jugal.
160. Dentary dorsal margin, form: straight or gently concave (0); convex (1).
161. External mandibular fnestra, length: 15-20% (0), or 40% (1), length of
lower jaw.
162. Caudal vertebrae, proportions of articular faces: witdth and height
subequal
(0); width twice height (1).
163. Anterior caudal (CA1-8) transverse processes, length: subequal to (0), or
approximately twice (1), corresonding neural spines.
165. Subacromial notch: absent (0); present (1).
175. Dentary teeth: present (0); absent (1).
190. Lower jaws, form of symphyseal region: V-shaped (0); spout-shaped (1).
196. Mid-cervical vertebrae (C3-C7), postzygapophyseal form: short, distal
epipophyses (0); long (overhanging) and arched with inset epipophyses (1).
--
*Note the obvious spam-defeating modification
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bull.net Cal King
<harshman.diespamdi...@user-2ivelqg.dialup.mindspring.com>,
Most of these characters deal with minute details of the skull. If one
refers to the illustration of Caudipteryx's skull in the original paper
(fig. 6 and 7), it is, as Feduccia describes, fragmentary. In fact,
Feduccia (1999:397) also provides an illustration of Caudipteryx's skull,
and points out that the detailed skull characters used in the cladistic
analyses cannot be confirmed on the extremely fragmentary specimens
themselves.
Further, none of the birdlike characters of Caudipteryx is included in the
list you just reposted. No wonder cladists insist that Caudipteryx is not
a bird. If one ignores evidence and/or relies on blind faith, one is
probably going to arrive at the wrong conclusion.
John Harshman
All of them? Even the presence/absence of dentary teeth? I remain amazed
that Feduccia can tell that Caudipteryx's skull is "birdlike", but Sereno
apparently can't get any actual characters from it. If "birdlike" actually
refers only to the position of the foramen magnum, that would explain
much, but the word would be stripped of most of its intended meaning,
wouldn't you agree?
> Further, none of the birdlike characters of Caudipteryx is included in the
> list you just reposted. No wonder cladists insist that Caudipteryx is not
> a bird. If one ignores evidence and/or relies on blind faith, one is
> probably going to arrive at the wrong conclusion.
You should list the birdlike characters. We'll see how they go.
bull.net Cal King
<harshman.diespamdi...@user-2ivekke.dialup.mindspring.com>,
I think you should search Deja News again. You presented a much shorter
list of uniquely Oviraptoran characters found in Caudipteryx before. So
some of the characters you listed here are, even by your own evaluation,
not uniquely oviraptoran.
>> Further, none of the birdlike characters of Caudipteryx is included in the
>> list you just reposted. No wonder cladists insist that Caudipteryx is not
>> a bird. If one ignores evidence and/or relies on blind faith, one is
>> probably going to arrive at the wrong conclusion.
>
>You should list the birdlike characters. We'll see how they go.
I have also listed them in my debate with Brochu. You can search Deja News
for those if you like. If not, I can do it for you. They are also listed
in the last chapter of Feduccia (1999).
alcal...@my-deja.com
Sorry to stick my nose in your entertaining debate, I just want to
know: What is Feduccia (1999)?
AJ
Sent via Deja.com
http://www.deja.com/
Evan Robinson
> harshman....@sjm.infi.net (John Harshman) wrote:
> You should list the birdlike characters. We'll see how they go.
I'll bite. Here are some of Feduccia's arguments that Caudiptteryx is a
flightless bird, and then I have a challenge afterwards:
Caudipteryx and Protoarchaeopteryx are replete with features of
secondarily flightless Mesozoic sauriurine birds (Feduccia, 1999)
including:
A short tail, similar to that of Confuciusornis, with some fusion of
the vertebrae and therefore a quasi-pygostyle.
Secondarily reduced wing feathers that attach to its hands in the same
manner as flighted birds such as Confuciusornis, locking up it’s hand
for any type of predatory function.
Birdlike skull with a posteroventral foramen magnum. In theropods,
foramen magnum is posterior and the neck enters the skull from behind.
No caudofemoralis or pelvic musculature that defines theropods.
The middle and third metatarsal is longer than the outer two, a
distinctive avian feature.
An avian style halux.
Waisted teeth like those of Archaeopteryx.
No furcula, common in flightless birds.
Reduced fibula, opisthopubic foot has no boot, acetubulum is
nontheropod-like.
Eats it’s food with gizzard stones.
Extensive suite of cursorial-bird-like locomotory characters (Jones et
al).
Here’s my challenge: Prove that Oviraptor did NOT descend from a
Jurassic bird. Consider this:
Although it is not considered advanced as far a Avetheropods go, it has
been flightless for many millions of years. I propose that it descended
from a bird with aprox 30 caudial vertbrae, two more than
Protoarcheopteryx.
1)I will accept the argument that volant animals will have an enlarged
cerebellum. There has been no study of this on oviraptors (that I can
find anyway). Its skull has been described as buldgy and bulbous. Its
cerebral vascular system is said to be avian. Regarding
Christotenotes, a late Cretaceous oviraptorosaur : “the large
cerebellar auricular (floccular) fossa is very deep and invades the
medial portion of the paroccipital process posterolaterally. …
posteriorly, the fossa has a distinct, round depression in its medial
wall.”(1)
2)Regarding an oviraptoroid skeleton in Ukhaa Tolgod:
The ventral part of the thorax is well preserved and provides evidence
for other avian features that were previously unreported in
oviraptorids, including the articulation of the first three thoratic
ribs with the coastal margin of the sternum and the presence of a
single, ossified ventral segent in each rib as well as ossified
uncinate processes associated with the thoratic ribs”(2)
3)This same oviraptor has keratinous claws that are strongly curved as
the manal claws of Archaeopteryx and the pedal claws of modern climbing
birds.
4)The oviraptor is the only dinosaur proven to have ratite-ornithoid
shelled eggs.
Has their ever been a study of Oviraptor bone histology or nasal
passages? Perhaps it descended from an Ornithurine bird, that would
explain why it lays on its eggs.
Thanks,
Evan Robinson
(1)Hans-Dieter Sues(1997).On Chirostenotes, A Late Cretaceous
Oviraptrosaur (Dinosauria: Theropoda from Western North America. JVP 17
(4) Dec 1997. Pgs:698-716
2) Clark, James, Mark Norell, and Luis Chiappe.(May, 1999) An
Oviraptorid Skeleton from the Late Cretaceous of Ukhaa Tolgod,
Mongolia, preserved in an Avianlike Brooding position over an
Oviraptoid nest. American Museum Novitates #3265.
Evan Robinson
> > harshman....@sjm.infi.net (John Harshman) wrote:
> You should list the birdlike characters. We'll see how they go.
>
I’ll bite:
Caudipteryx and Protoarchaeopteryx are replete with features of
secondarily flightless Mesozoic sauriiurine birds (Feduccia, 1999)
including (also from Feduccia 1999, 2nd edition):
A short tail, similar to that of Confuciusornis, with some fusion of
the vertebrae and therefore a quasi-pygostyle.
Secondarily reduced wing feathers that attach to its hands in the same
manner as flighted birds such as Confuciusornis, locking up it’s hand
for any type of predatory function.
Birdlike skull with a posteroventral foramen magnum. In theropods,
foramen magnum is posterior and the neck enters the skull from behind.
No caudofemoralis or pelvic musculature that defines theropods.
The middle and third metatarsal is longer than the outer two, a
distinctive avian feature.
An avian style halux.
Waisted teeth like those of Archaeopteryx.
No furcula, common in flightless birds.
Reduced fibula, opisthopubic foot has no boot, acetubulum is
nontheropod-like.
Eats it’s food with gizzard stones.
Extensive suite of cursorial-bird-like locomotory characters (Jones et
al).
Here’s my challenge: Prove that Oviraptor did NOT descend from a
Jurassic bird. Consider this:
Although it is not considered advanced as far a Avitheropods go, it has
been flightless for many millions of years. I propose that it descended
from a bird with aprox 30 caudial vertbrae, two more than
Protoarcheopteryx.
I would accept the argument that volant animals will have an enlarged
cerebellum, however, there has been no study of this on oviraptors
Thanks,
Evan Robinson
>previous post:
> Http://members.xoom.com/TheEggSpot/dinoeggs.htm
John Harshman
You seem to have ignored my question, and I would be very interested in an
answer.
> I think you should search Deja News again. You presented a much shorter
> list of uniquely Oviraptoran characters found in Caudipteryx before. So
> some of the characters you listed here are, even by your own evaluation,
> not uniquely oviraptoran.
As I said, these are all the characters that change at the relevant node.
If you will search DejaNews again, you will discover the post in which I
tell you which ones are unique (most of them).
> >> Further, none of the birdlike characters of Caudipteryx is included in the
> >> list you just reposted. No wonder cladists insist that Caudipteryx is not
> >> a bird. If one ignores evidence and/or relies on blind faith, one is
> >> probably going to arrive at the wrong conclusion.
> >
> >You should list the birdlike characters. We'll see how they go.
>
> I have also listed them in my debate with Brochu. You can search Deja News
> for those if you like. If not, I can do it for you. They are also listed
> in the last chapter of Feduccia (1999).
I took a look a while ago. If I recall, there's only a single cranial
character (the afore-mentioned foramen magnum), and a couple of others
that don't seem particularly more impressive than Sereno's. Perhaps you
could list them again. After all, I did it for you.
John Harshman
> Sorry to stick my nose in your entertaining debate, I just want to
> know: What is Feduccia (1999)?
Feduccia, A. 1999. The origin and evolution of birds, second edition. Yale
University Press, New Haven.
John Harshman
<theeg...@my-deja.com> wrote:
> > harshman....@sjm.infi.net (John Harshman) wrote:
> > You should list the birdlike characters. We'll see how they go.
>
> I'll bite. Here are some of Feduccia's arguments that Caudiptteryx is a
> flightless bird, and then I have a challenge afterwards:
>
> Caudipteryx and Protoarchaeopteryx are replete with features of
> secondarily flightless Mesozoic sauriurine birds (Feduccia, 1999)
> including:
>
> A short tail, similar to that of Confuciusornis, with some fusion of
> the vertebrae and therefore a quasi-pygostyle.
Many derived theropods have shortened tails. Better score this character
for them too and see what happens.
> Secondarily reduced wing feathers that attach to its hands in the same
> manner as flighted birds such as Confuciusornis, locking up it’s hand
> for any type of predatory function.
No preservation of such structures in most taxa, so it would have to be
scored as missing data in most of the matrix.
> Birdlike skull with a posteroventral foramen magnum. In theropods,
> foramen magnum is posterior and the neck enters the skull from behind.
Potentially one character, although he should be careful to score other
oviraptorosaurs too. (Apparently, "posteroventral foramen magnum" is the
only scorable feature of the skull that makes it birdlike. Rather an
overstatement, wouldn't you think?)
> No caudofemoralis or pelvic musculature that defines theropods.
Not clear on what he means by the second part. For the first part,
apparently he can tell from lack of muscle scars (?) that Caudipteryx at
least had a reduced caudofemoralis. I don't know how he could tell if it
were absent, and anyway most birds have one.
> The middle and third metatarsal is longer than the outer two, a
> distinctive avian feature.
Interesting character. I don't have enough good illustrations to tell what
the condition is in any other derived theropods, particularly
oviraptorosaurs.
> An avian style halux.
Not well enough defined to be scorable in other taxa.
> Waisted teeth like those of Archaeopteryx.
Also found in some other theropods, e.g. Microraptor. Better score this
for everyone too.
> No furcula, common in flightless birds.
Furculae are very commonly not preserved. Check out the known distribution
within theropods and see what I mean.
> Reduced fibula, opisthopubic foot has no boot, acetubulum is
> nontheropod-like.
The last is too vaguely defined to score. The second is just plain wrong;
Caudipteryx has a clear boot. The first is interesting, and some other
theropods also have reduced fibulae.
> Eats it’s food with gizzard stones.
Seems to be an autapomorphy, as far as I can tell. Unless you know of any
gizzard stones for Archaeopteryx.
> Extensive suite of cursorial-bird-like locomotory characters (Jones et
> al).
Too vague to score, and inferred from the actual anatomical characters,
which it would be better to score.
> Here’s my challenge: Prove that Oviraptor did NOT descend from a
> Jurassic bird. Consider this:
Operationally, how would this be done? If other oviraptorosaurs are
allowed to be birds too, why not other maniraptorans? Can we even test
this on a well-resolved phylogeny?
What exactly does that mean?
> Has their ever been a study of Oviraptor bone histology or nasal
> passages? Perhaps it descended from an Ornithurine bird, that would
> explain why it lays on its eggs.
>
> Thanks,
>
> Evan Robinson
>
> (1)Hans-Dieter Sues(1997).On Chirostenotes, A Late Cretaceous
> Oviraptrosaur (Dinosauria: Theropoda from Western North America. JVP 17
> (4) Dec 1997. Pgs:698-716
>
> 2) Clark, James, Mark Norell, and Luis Chiappe.(May, 1999) An
> Oviraptorid Skeleton from the Late Cretaceous of Ukhaa Tolgod,
> Mongolia, preserved in an Avianlike Brooding position over an
> Oviraptoid nest. American Museum Novitates #3265.
>
>
>
>
> Sent via Deja.com
> http://www.deja.com/
--
bull.net Cal King
>Here’s my challenge: Prove that Oviraptor did NOT descend from a
>Jurassic bird. Consider this:
>Although it is not considered advanced as far a Avetheropods go, it has
>been flightless for many millions of years.
How can you tell? Is it because it has no obvious flight adaptations?
>I propose that it descended
>from a bird with aprox 30 caudial vertbrae, two more than
>Protoarcheopteryx.
What is the evidence that Oviraptor is a bird descendant?
>1)I will accept the argument that volant animals will have an enlarged
>cerebellum. There has been no study of this on oviraptors (that I can
>find anyway). Its skull has been described as buldgy and bulbous. Its
>cerebral vascular system is said to be avian. Regarding
>Christotenotes, a late Cretaceous oviraptorosaur : “the large
>cerebellar auricular (floccular) fossa is very deep and invades the
>medial portion of the paroccipital process posterolaterally. …
>posteriorly, the fossa has a distinct, round depression in its medial
>wall.”(1)
In a paper published in 1956, de Beer used the enlarged cerebellum to
refute Lowe's theory that the ratites are descended directly from theropods
(Feduccia 1996). The same reasoning can be used to refute the hypothesis
that some theropods are secondarily flightless birds. None of them has an
enlarged cerebellum, Brochu's mumbo jumbo about the cast of a T. rex skull
notwithstaning.
>2)Regarding an oviraptoroid skeleton in Ukhaa Tolgod:
>The ventral part of the thorax is well preserved and provides evidence
>for other avian features that were previously unreported in
>oviraptorids, including the articulation of the first three thoratic
>ribs with the coastal margin of the sternum and the presence of a
>single, ossified ventral segent in each rib as well as ossified
>uncinate processes associated with the thoratic ribs”(2)
In addition to the enlarged cerebellum, the ratites also retained other
traces of a volant ancestry:
1. vestigial flight quills on the wing of the cassowary
2. a wing skeleton built on the same general plan as that of flying birds,
3. the fusion of of several carpal elements to form a "flight"
carpometacarpus
4. tail vertebrae fused to form the uniquely avian pygostyle.
5. feathers on the first digit are still arranged to form an alula, or
midwing slot, clearly a carinate adaptation for flight.
One can also find some of these "ratite" features in the bird Caudipteryx,
specifically wing feathers and pygostyle. If one wishes to claim that
Oviraptor is a secondarily flightless bird, then one can certainly search
for these or other evidence of a volant ancestor.
>3)This same oviraptor has keratinous claws that are strongly curved as
>the manal claws of Archaeopteryx and the pedal claws of modern climbing
>birds.
Keratinous claw is a reptilian feature as well. Has there been any
measurements taken on claw geometry? Cursorial birds do not have the
climbing claws of arboreal birds. Why would Oviraptor had such seemingly
maladaptive claw geometry since it is not arboreal and higly recurved
claws will get in the way of its running?
>4)The oviraptor is the only dinosaur proven to have ratite-ornithoid
>shelled eggs.
As has been pointed out in the past, the association of fossil eggs with
adult dinosaurs is tenuous at best.
bull.net Cal King
<harshman.diespamdi...@user-2ivekps.dialup.mindspring.com>,
harshman....@sjm.infi.net (John Harshman) wrote:
>Many derived theropods have shortened tails. Better score this character
>for them too and see what happens.
Which "theropods" have shortened tails? The ostrich? The wood duck?
>> Secondarily reduced wing feathers that attach to its hands in the same
>> manner as flighted birds such as Confuciusornis, locking up it’s hand
>> for any type of predatory function.
>
>No preservation of such structures in most taxa, so it would have to be
>scored as missing data in most of the matrix.
But the fact that this character is present cannot be used? This is a
blatant attempt to ignore evidence.
>> Birdlike skull with a posteroventral foramen magnum. In theropods,
>> foramen magnum is posterior and the neck enters the skull from behind.
>
>Potentially one character, although he should be careful to score other
>oviraptorosaurs too. (Apparently, "posteroventral foramen magnum" is the
>only scorable feature of the skull that makes it birdlike. Rather an
>overstatement, wouldn't you think?)
If oviraptorosaurs have this character, then why did the cladists not
include it in their analyses? This is another character that has been
ignored by the cladists.
>> No caudofemoralis or pelvic musculature that defines theropods.
>
>Not clear on what he means by the second part. For the first part,
>apparently he can tell from lack of muscle scars (?) that Caudipteryx at
>least had a reduced caudofemoralis. I don't know how he could tell if it
>were absent, and anyway most birds have one.
The massive caudofemoralis muscle that is part of the theropod bauplan is
definitely missing. What little muscle there, if present, can only be used
to wag the short tail, as in modern birds.
>> The middle and third metatarsal is longer than the outer two, a
>> distinctive avian feature.
>
>Interesting character. I don't have enough good illustrations to tell what
>the condition is in any other derived theropods, particularly
>oviraptorosaurs.
>
>> An avian style halux.
>
>Not well enough defined to be scorable in other taxa.
That is quite simply "cladospeak".
>> Waisted teeth like those of Archaeopteryx.
>
>Also found in some other theropods, e.g. Microraptor. Better score this
>for everyone too.
Microraptor is identified as a theropod largely on the basis of the
rod-like extensions of its tail. Its identity is far from certain.
>> No furcula, common in flightless birds.
>
>Furculae are very commonly not preserved. Check out the known distribution
>within theropods and see what I mean.
Yes, they are not preserved because most theropods lack a furcula. It is
commonly preserved in animals that have them, including Longisquama.
>> Reduced fibula, opisthopubic foot has no boot, acetubulum is
>> nontheropod-like.
>
>The last is too vaguely defined to score. The second is just plain wrong;
The distal end of the pubis is slightly larger than the shaft in birds, but
it is by no means a boot. Compare the pubic "boot" of Archaeopteryx with
that of Rahonavis and T. rex, and one can see why many believe Rahonavis is
a chimera with a theropod pelvis.
>Caudipteryx has a clear boot.
Have you seen the actual specimen?
>The first is interesting, and some other
>theropods also have reduced fibulae.
What about acetabulum not theropod-like? Can we ignore that also?
>> Eats it’s food with gizzard stones.
>
>Seems to be an autapomorphy, as far as I can tell. Unless you know of any
>gizzard stones for Archaeopteryx.
No theropod has any gizzard stones. The only "theropod" that does is
Caudipteryx.
>> Extensive suite of cursorial-bird-like locomotory characters (Jones et
>> al).
>
>Too vague to score, and inferred from the actual anatomical characters,
>which it would be better to score.
More characters to ignore? What happened to your "congruence with other
characters" belief? Not applicable here?
John Harshman
getulus@no bull.net (Cal King) wrote:
> In article
> <harshman.diespamdi...@user-2ivekps.dialup.mindspring.com>,
> harshman....@sjm.infi.net (John Harshman) wrote:
>
> >Many derived theropods have shortened tails. Better score this character
> >for them too and see what happens.
>
> Which "theropods" have shortened tails? The ostrich? The wood duck?
Aside from them, reduction in the number of caudals is a common event in
derived theropods. No other non-avian theropod that I know of has as few
caudals as Caudipteryx, but Oviraptor has fewer than most other theropods
also.
> >> Secondarily reduced wing feathers that attach to its hands in the same
> >> manner as flighted birds such as Confuciusornis, locking up it’s hand
> >> for any type of predatory function.
> >
> >No preservation of such structures in most taxa, so it would have to be
> >scored as missing data in most of the matrix.
>
> But the fact that this character is present cannot be used? This is a
> blatant attempt to ignore evidence.
You must understand that if it's missing data for most taxa, the character
will tend not to be very informative. That is, it will be equally
compatible with most hypotheses of phylogeny.
> >> Birdlike skull with a posteroventral foramen magnum. In theropods,
> >> foramen magnum is posterior and the neck enters the skull from behind.
> >
> >Potentially one character, although he should be careful to score other
> >oviraptorosaurs too. (Apparently, "posteroventral foramen magnum" is the
> >only scorable feature of the skull that makes it birdlike. Rather an
> >overstatement, wouldn't you think?)
>
> If oviraptorosaurs have this character, then why did the cladists not
> include it in their analyses? This is another character that has been
> ignored by the cladists.
If oviraptorosaurs don't have this character, then why did Feduccia not
include that in his analyses? I don't know how it should be scored in many
other theropods, and neither do you.
> >> No caudofemoralis or pelvic musculature that defines theropods.
> >
> >Not clear on what he means by the second part. For the first part,
> >apparently he can tell from lack of muscle scars (?) that Caudipteryx at
> >least had a reduced caudofemoralis. I don't know how he could tell if it
> >were absent, and anyway most birds have one.
>
> The massive caudofemoralis muscle that is part of the theropod bauplan is
> definitely missing. What little muscle there, if present, can only be used
> to wag the short tail, as in modern birds.
Like I said. It's reduction of the caudofemoralis that is the character. I
would expect that to be correlated with shortening of the tail, wouldn't
you? Better downweight it.
> >> The middle and third metatarsal is longer than the outer two, a
> >> distinctive avian feature.
> >
> >Interesting character. I don't have enough good illustrations to tell what
> >the condition is in any other derived theropods, particularly
> >oviraptorosaurs.
> >
> >> An avian style halux.
> >
> >Not well enough defined to be scorable in other taxa.
>
> That is quite simply "cladospeak".
No. A character needs to be described in such a way that somebody else,
looking at another taxon, can tell which state it has. "avian style"
doesn't do that.
> >> Waisted teeth like those of Archaeopteryx.
> >
> >Also found in some other theropods, e.g. Microraptor. Better score this
> >for everyone too.
>
> Microraptor is identified as a theropod largely on the basis of the
> rod-like extensions of its tail. Its identity is far from certain.
I think Cal might be in the process of turning Microraptor into a bird. If
so, this creates problems of character distribution all its own, probably
more than it solves for him. The presence of *serrated*, waisted teeth,
for example.
> >> No furcula, common in flightless birds.
> >
> >Furculae are very commonly not preserved. Check out the known distribution
> >within theropods and see what I mean.
>
> Yes, they are not preserved because most theropods lack a furcula. It is
> commonly preserved in animals that have them, including Longisquama.
If most theropods indeed lack a furcula, then furculae have evolved
convergently many times. But however can you make that claim?
> >> Reduced fibula, opisthopubic foot has no boot, acetubulum is
> >> nontheropod-like.
> >
> >The last is too vaguely defined to score. The second is just plain wrong;
>
> The distal end of the pubis is slightly larger than the shaft in birds, but
> it is by no means a boot. Compare the pubic "boot" of Archaeopteryx with
> that of Rahonavis and T. rex, and one can see why many believe Rahonavis is
> a chimera with a theropod pelvis.
>
> >Caudipteryx has a clear boot.
>
> Have you seen the actual specimen?
Yes. Have you?
> >The first is interesting, and some other
> >theropods also have reduced fibulae.
>
> What about acetabulum not theropod-like? Can we ignore that also?
Could you score that for a new taxon? Needs a better description.
> >> Eats it’s food with gizzard stones.
> >
> >Seems to be an autapomorphy, as far as I can tell. Unless you know of any
> >gizzard stones for Archaeopteryx.
>
> No theropod has any gizzard stones. The only "theropod" that does is
> Caudipteryx.
Like I said, an autapomorphy, and not informative.
> >> Extensive suite of cursorial-bird-like locomotory characters (Jones et
> >> al).
> >
> >Too vague to score, and inferred from the actual anatomical characters,
> >which it would be better to score.
>
> More characters to ignore? What happened to your "congruence with other
> characters" belief? Not applicable here?
I could say that Caudipteryx has a theropod-like femur, and call that a
character. How would you refute me? I haven't told you what
"theropod-like" means. Same for these characters. Explain them adequately
for scoring, or they must be ignored.
bull.net Cal King
<harshman.diespamdi...@user-2ivekou.dialup.mindspring.com>,
>In article <uAcf6.12379$mA1.7...@bgtnsc06-news.ops.worldnet.att.net>,
>getulus@no bull.net (Cal King) wrote:
>> Which "theropods" have shortened tails? The ostrich? The wood duck?
>
>Aside from them, reduction in the number of caudals is a common event in
>derived theropods. No other non-avian theropod that I know of has as few
>caudals as Caudipteryx,
Pretty strong evidence that Caudipteryx is a bird.
> but Oviraptor has fewer than most other theropods
>also.
>
>> >> Secondarily reduced wing feathers that attach to its hands in the same
>> >> manner as flighted birds such as Confuciusornis, locking up it’s hand
>> >> for any type of predatory function.
>You must understand that if it's missing data for most taxa, the character
>will tend not to be very informative. That is, it will be equally
>compatible with most hypotheses of phylogeny.
You must instead understand that it is "missing data" for all, not most,
theropods. It is also "missing data" for all pterosaurs. All known
theropods and pterosaurs lack wing feathers.
>> >> Birdlike skull with a posteroventral foramen magnum. In theropods,
>> >> foramen magnum is posterior and the neck enters the skull from behind.
>If oviraptorosaurs don't have this character, then why did Feduccia not
>include that in his analyses? I don't know how it should be scored in many
>other theropods, and neither do you.
That does not answer my question. Why did Sereno omit this character if it
is in fact present in some oviraptorosaurs?
>> >> No caudofemoralis or pelvic musculature that defines theropods.
>Like I said. It's reduction of the caudofemoralis that is the character. I
>would expect that to be correlated with shortening of the tail, wouldn't
>you? Better downweight it.
Don't understand your point at all. Birds have shortened tails and thus
their caudofemoralis is reduced. Theropods do not have shortened tails;
they have a more massive caudofemoralis. That shows Caudipteryx is more
birdlike than theropodlike. Why do we "downweight" this character, unless
one wants to de-emphasize the birdlike characters of Caudipteryx so that
one can claim it is not a bird?
>> >> An avian style halux.
>No. A character needs to be described in such a way that somebody else,
>looking at another taxon, can tell which state it has. "avian style"
>doesn't do that.
How about the reversed hallux? Would that be a strong avian character?
>I think Cal might be in the process of turning Microraptor into a bird. If
>so, this creates problems of character distribution all its own, probably
>more than it solves for him. The presence of *serrated*, waisted teeth,
>for example.
I am not turning it into anything. I merely point out that it is not
positively identified as either a bird or a theropod. Besides, the
serrated teeth is a drawing, not a photograph. We know that many cladists
have in the past been fooled by wishful thinking into seeing serrations on
the teeth of Protarchaeopteryx.
>If most theropods indeed lack a furcula, then furculae have evolved
>convergently many times. But however can you make that claim?
It is an adaptive character. Adaptive characters often evolve
independently in different lineages.
>> >Caudipteryx has a clear boot.
>>
>> Have you seen the actual specimen?
>
>Yes. Have you?
No I have not seen it. But since you had claimed that Protarchaeopteryx
had serrated teeth and then backed away from that claim, your observations
are less reliable than those of Feduccia. I believe Feduccia's claim that
Caudipteryx does not have a theropod style pubic boot.
>> What about acetabulum not theropod-like? Can we ignore that also?
>
>Could you score that for a new taxon? Needs a better description.
That means you are ignoring yet another character that shows Caudipteryx is
not a theropod.
>> No theropod has any gizzard stones. The only "theropod" that does is
>> Caudipteryx.
>Like I said, an autapomorphy, and not informative.
Yes, all of the birdlike characters in Caudipteryx are avian
autapomorphies. But they are informative if one is trying to figure out
what kind of beast it was. The misidentification of Caudipteryx is thus
yet another example of the weakness of cladistic methodology.
>I could say that Caudipteryx has a theropod-like femur, and call that a
>character. How would you refute me? I haven't told you what
>"theropod-like" means. Same for these characters. Explain them adequately
>for scoring, or they must be ignored.
If you want to claim that, then go ahead and do so. It is your
prerogative.
John Harshman
getulus@no bull.net (Cal King) wrote:
> In article
> <harshman.diespamdi...@user-2ivekou.dialup.mindspring.com>,
> harshman....@sjm.infi.net (John Harshman) wrote:
> >In article <uAcf6.12379$mA1.7...@bgtnsc06-news.ops.worldnet.att.net>,
> >getulus@no bull.net (Cal King) wrote:
>
> >> Which "theropods" have shortened tails? The ostrich? The wood duck?
> >
> >Aside from them, reduction in the number of caudals is a common event in
> >derived theropods. No other non-avian theropod that I know of has as few
> >caudals as Caudipteryx,
>
> Pretty strong evidence that Caudipteryx is a bird.
Not by your standards, since reduction in the number of caudals happens
convergently in many taxa. By my standards, it's one character among many,
and most of them conflict with that theory.;
> > but Oviraptor has fewer than most other theropods
> >also.
> >
> >> >> Secondarily reduced wing feathers that attach to its hands in the same
> >> >> manner as flighted birds such as Confuciusornis, locking up it’s hand
> >> >> for any type of predatory function.
>
> >You must understand that if it's missing data for most taxa, the character
> >will tend not to be very informative. That is, it will be equally
> >compatible with most hypotheses of phylogeny.
>
> You must instead understand that it is "missing data" for all, not most,
> theropods. It is also "missing data" for all pterosaurs. All known
> theropods and pterosaurs lack wing feathers.
You must understand what "missing data" means. It doesn't mean you score
the animal as lacking that state. It means you can't score that animal at
all, as either having or lacking the state. Sorry.
> >> >> Birdlike skull with a posteroventral foramen magnum. In theropods,
> >> >> foramen magnum is posterior and the neck enters the skull from behind.
>
> >If oviraptorosaurs don't have this character, then why did Feduccia not
> >include that in his analyses? I don't know how it should be scored in many
> >other theropods, and neither do you.
>
> That does not answer my question. Why did Sereno omit this character if it
> is in fact present in some oviraptorosaurs?
Sereno omitted the character (I suppose, not being able to read minds)
because he didn't notice it, or because he didn't think it was possible to
score reliably, or some other reason I haven't thought of. Characters tend
to accumulate over time, because people notice features that weren't
noticed before. It's considered kosher to use characters people have used
in previous analyses, or else to explain why you didn't. Since Feduccia's
"analysis" came after Sereno's, the question is why Feduccia didn't use
Sereno's characters.
> >> >> No caudofemoralis or pelvic musculature that defines theropods.
>
> >Like I said. It's reduction of the caudofemoralis that is the character. I
> >would expect that to be correlated with shortening of the tail, wouldn't
> >you? Better downweight it.
>
> Don't understand your point at all. Birds have shortened tails and thus
> their caudofemoralis is reduced. Theropods do not have shortened tails;
> they have a more massive caudofemoralis. That shows Caudipteryx is more
> birdlike than theropodlike. Why do we "downweight" this character, unless
> one wants to de-emphasize the birdlike characters of Caudipteryx so that
> one can claim it is not a bird?
Because it's considered bad form to score the same thing twice. If you
have used "short tail" as a character, using "reduced caudofemoralis" is
just another way to say the same thing. You are pretending to have twice
as much evidence as you really do have. (Assuming you agree that one is a
consequence of the other.)
> >> >> An avian style halux.
>
> >No. A character needs to be described in such a way that somebody else,
> >looking at another taxon, can tell which state it has. "avian style"
> >doesn't do that.
>
> How about the reversed hallux? Would that be a strong avian character?
Better. At least one might hope to score it. Does Caudipteryx have a
reversed hallux?
> >I think Cal might be in the process of turning Microraptor into a bird. If
> >so, this creates problems of character distribution all its own, probably
> >more than it solves for him. The presence of *serrated*, waisted teeth,
> >for example.
>
> I am not turning it into anything. I merely point out that it is not
> positively identified as either a bird or a theropod.
Why? It would seem to be an easy thing to do, considering the giant
morphological gap between the two. Or so you would say. Why can't you do
it yourself?
> Besides, the
> serrated teeth is a drawing, not a photograph. We know that many cladists
> have in the past been fooled by wishful thinking into seeing serrations on
> the teeth of Protarchaeopteryx.
A strong accusation. Shall we refuse to accept all drawings as evidence
from now on, or just drawings produced by people who think birds are
dinosaurs?
> >If most theropods indeed lack a furcula, then furculae have evolved
> >convergently many times. But however can you make that claim?
>
> It is an adaptive character. Adaptive characters often evolve
> independently in different lineages.
You are saying that clavicles have been lost and regained many times in
theropods? Wouldn't that contradict Dollo's law?
> >> >Caudipteryx has a clear boot.
> >>
> >> Have you seen the actual specimen?
> >
> >Yes. Have you?
>
> No I have not seen it. But since you had claimed that Protarchaeopteryx
> had serrated teeth and then backed away from that claim, your observations
> are less reliable than those of Feduccia. I believe Feduccia's claim that
> Caudipteryx does not have a theropod style pubic boot.
Then why did you ask if I had seen it?
> >> What about acetabulum not theropod-like? Can we ignore that also?
> >
> >Could you score that for a new taxon? Needs a better description.
>
> That means you are ignoring yet another character that shows Caudipteryx is
> not a theropod.
It's not a character until you define it to the point where we can tell if
an animal has it or not.
> >> No theropod has any gizzard stones. The only "theropod" that does is
> >> Caudipteryx.
>
> >Like I said, an autapomorphy, and not informative.
>
> Yes, all of the birdlike characters in Caudipteryx are avian
> autapomorphies.
You should look up the definition of autapomorphy. In this case, any
characters Caudipteryx shares with birds are synapomorphies, not
autapomorphies. But gizzard stones can't be such a character, since they
are unknown for fossil birds (actually, I don't know of any; do you?).
Unless you are claiming that Caudipteryx is a highly derived bird, sister
taxon to some bird that does have known gizzard stones, it's either
convergent between Caudipteryx and that bird, or gizzard stones happened
never to be preserved in all intervening birds. That's missing data
(remember?), and hence uninformative.
> But they are informative if one is trying to figure out
> what kind of beast it was. The misidentification of Caudipteryx is thus
> yet another example of the weakness of cladistic methodology.
No, they are not informative. As I have explained. What you are saying is
that some birds have gizzard stones, Caudipteryx has gizzard stones,
therefore Caudipteryx is a bird. For this to work, there would have to be
some clade of birds for which gizzard stones were a synapomorphy, and
Caudipteryx would have to belong to that clade. You can't define such a
clade. And of course there are convergences in evolution of gizzard stones
within dinosaurs, so it's a useless character anyway by your standards.
> >I could say that Caudipteryx has a theropod-like femur, and call that a
> >character. How would you refute me? I haven't told you what
> >"theropod-like" means. Same for these characters. Explain them adequately
> >for scoring, or they must be ignored.
>
> If you want to claim that, then go ahead and do so. It is your
> prerogative.
No counterargument?
bull.net Cal King
<harshman.diespamdi...@user-2ivekgk.dialup.mindspring.com>,
harshman....@sjm.infi.net (John Harshman) wrote:
>> >Aside from them, reduction in the number of caudals is a common event in
>> >derived theropods. No other non-avian theropod that I know of has as few
>> >caudals as Caudipteryx,
>>
>> Pretty strong evidence that Caudipteryx is a bird.
>
>Not by your standards, since reduction in the number of caudals happens
>convergently in many taxa. By my standards, it's one character among many,
>and most of them conflict with that theory.;
That is a strawman argument because I have said that even though the three
fingered hand is not a synapomorphy between birds and theropods, it can
still be used in theropod phylogeny since some theropods have fewer, and
some more than, 3 fingers.
>> You must instead understand that it is "missing data" for all, not most,
>> theropods. It is also "missing data" for all pterosaurs. All known
>> theropods and pterosaurs lack wing feathers.
>
>You must understand what "missing data" means. It doesn't mean you score
>the animal as lacking that state. It means you can't score that animal at
>all, as either having or lacking the state. Sorry.
It means that all pterosaurs and theropods are missing wing feathers. If
you assume that theropods have wing feathers, you are taking an
unusually big leap of faith for a scientist, but a routine leap for many
cladistic palontologists who support the bird-theropod link. In any case,
this is evidence that Caudipteryx is a bird, but of course those who argue
that it is not a bird will simply ignore such evidence.
>> That does not answer my question. Why did Sereno omit this character if it
>> is in fact present in some oviraptorosaurs?
>
>Sereno omitted the character (I suppose, not being able to read minds)
>because he didn't notice it,
Or perhaps because he did not think that oviraptorosaurs have a
posteroventral foramen magnum.
> or because he didn't think it was possible to
>score reliably, or some other reason I haven't thought of. Characters tend
>to accumulate over time, because people notice features that weren't
>noticed before. It's considered kosher to use characters people have used
>in previous analyses, or else to explain why you didn't. Since Feduccia's
>"analysis" came after Sereno's, the question is why Feduccia didn't use
>Sereno's characters.
That does not matter. He claims that the characters used in the original
analysis by Ji et al. are either symplesiomorphies or they are not
verifiable on the fragmentary skull of Caudipteryx. Since symplesiomorphs
are useless in ascertaining branching order, he did not use the characters
that some cladists used.
>> Don't understand your point at all. Birds have shortened tails and thus
>> their caudofemoralis is reduced. Theropods do not have shortened tails;
>> they have a more massive caudofemoralis. That shows Caudipteryx is more
>> birdlike than theropodlike. Why do we "downweight" this character, unless
>> one wants to de-emphasize the birdlike characters of Caudipteryx so that
>> one can claim it is not a bird?
>
>Because it's considered bad form to score the same thing twice.
Caudofemoralis and short tail are different things.
>If you
>have used "short tail" as a character, using "reduced caudofemoralis" is
>just another way to say the same thing.
You are arguing for character non-independence. By ignoring some
characters because they are missing in theropods, ignoring some because
they are avian autapomorphies, and finally ignoring others because they are
supposedly part of a suite, you have managed to ignore practically all of
the avian characters of Caudipteryx! No wonder you can argue that it is
not a bird. If I ignore all the reptilian characters of the fence lizard,
I can call it an amphibian too.
> You are pretending to have twice
>as much evidence as you really do have. (Assuming you agree that one is a
>consequence of the other.)
Actually I have no evidence at all according to you since all of the
evidence can be ignored.
>> How about the reversed hallux? Would that be a strong avian character?
>Better. At least one might hope to score it. Does Caudipteryx have a
>reversed hallux?
Yes, but you can ignore this one as well because it is an avian
autapomorphy.
>> >I think Cal might be in the process of turning Microraptor into a bird. If
>> >so, this creates problems of character distribution all its own, probably
>> >more than it solves for him. The presence of *serrated*, waisted teeth,
>> >for example.
>>
>> I am not turning it into anything. I merely point out that it is not
>> positively identified as either a bird or a theropod.
>
>Why? It would seem to be an easy thing to do, considering the giant
>morphological gap between the two. Or so you would say. Why can't you do
>it yourself?
Partly because it is not as well preserved as some other fossils from the
same locality, and partly because there may be observational mistakes. For
example, they claim that Microraptor has a sickle claw. This is not
verifiable based on their drawing. They also claim that the teeth are
serrated, but no actual photograph was presented. Hence it is prudent to
wait until other experts have had the chance to look at it before we
uncritically accept the author's opinions.
>> It is an adaptive character. Adaptive characters often evolve
>> independently in different lineages.
>
>You are saying that clavicles have been lost and regained many times in
>theropods? Wouldn't that contradict Dollo's law?
I am not saying that. You are.
>> >> >Caudipteryx has a clear boot.
>> >>
>> >> Have you seen the actual specimen?
>> >
>> >Yes. Have you?
>>
>> No I have not seen it. But since you had claimed that Protarchaeopteryx
>> had serrated teeth and then backed away from that claim, your observations
>> are less reliable than those of Feduccia. I believe Feduccia's claim that
>> Caudipteryx does not have a theropod style pubic boot.
>
>Then why did you ask if I had seen it?
That is because the end of the pubis is obscured by rock in the
illustrations accompanying the paper. Perhaps more rock has since been
removed.
>> >> What about acetabulum not theropod-like? Can we ignore that also?
>> >
>> >Could you score that for a new taxon? Needs a better description.
>>
>> That means you are ignoring yet another character that shows Caudipteryx is
>> not a theropod.
>
>It's not a character until you define it to the point where we can tell if
>an animal has it or not.
That means you cannot tell whether Caudipteryx has it or not. Then you
have no data to dispute Feduccia's observation.
>> >> No theropod has any gizzard stones. The only "theropod" that does is
>> >> Caudipteryx.
>>
>> >Like I said, an autapomorphy, and not informative.
>>
>> Yes, all of the birdlike characters in Caudipteryx are avian
>> autapomorphies.
>
>You should look up the definition of autapomorphy. In this case, any
>characters Caudipteryx shares with birds are synapomorphies, not
>autapomorphies. But gizzard stones can't be such a character, since they
>are unknown for fossil birds (actually, I don't know of any; do you?).
Gizzard stones are well known in living birds.
>Unless you are claiming that Caudipteryx is a highly derived bird, sister
>taxon to some bird that does have known gizzard stones, it's either
>convergent between Caudipteryx and that bird, or gizzard stones happened
>never to be preserved in all intervening birds. That's missing data
>(remember?), and hence uninformative.
The use of gizzard stones is convergent between Caudipteryx and other
living birds, yes. But since no known theropod has gizzard stones, it is
one more fact arguing against the identity of Caudipteryx as a theropod.
>> But they are informative if one is trying to figure out
>> what kind of beast it was. The misidentification of Caudipteryx is thus
>> yet another example of the weakness of cladistic methodology.
>
>No, they are not informative. As I have explained. What you are saying is
>that some birds have gizzard stones, Caudipteryx has gizzard stones,
>therefore Caudipteryx is a bird. For this to work, there would have to be
>some clade of birds for which gizzard stones were a synapomorphy, and
>Caudipteryx would have to belong to that clade. You can't define such a
>clade. And of course there are convergences in evolution of gizzard stones
>within dinosaurs, so it's a useless character anyway by your standards.
Gizzard stones is not a taxonomic character, I agree. However, it is
important to remember that phylogeny cannot be directly observed, but must
be inferred, and often from facts that are not directly phylogenetic (G.G.
Simpson 1984). Hence it is not a good idea to ignore such important facts
as the presence of gizzard stones, because it is consistent with a
vegetarian diet and because it is inconsistent with the claim that
Caudipteryx is a theropod, since theropods are carnivores with serrated
teeth.
>> >I could say that Caudipteryx has a theropod-like femur, and call that a
>> >character. How would you refute me? I haven't told you what
>> >"theropod-like" means. Same for these characters. Explain them adequately
>> >for scoring, or they must be ignored.
>>
>> If you want to claim that, then go ahead and do so. It is your
>> prerogative.
>
>No counterargument?
None is necessary.
John Harshman
getulus@no bull.net (Cal King) wrote:
> In article
> <harshman.diespamdi...@user-2ivekgk.dialup.mindspring.com>,
> harshman....@sjm.infi.net (John Harshman) wrote:
>
> >> >Aside from them, reduction in the number of caudals is a common event in
> >> >derived theropods. No other non-avian theropod that I know of has as few
> >> >caudals as Caudipteryx,
> >>
> >> Pretty strong evidence that Caudipteryx is a bird.
> >
> >Not by your standards, since reduction in the number of caudals happens
> >convergently in many taxa. By my standards, it's one character among many,
> >and most of them conflict with that theory.;
>
> That is a strawman argument because I have said that even though the three
> fingered hand is not a synapomorphy between birds and theropods, it can
> still be used in theropod phylogeny since some theropods have fewer, and
> some more than, 3 fingers.
I forgot that you have a magic method of telling in advance which
characters converge, and how often, without resorting to any phylogeny.
It's of course obvious that the foramen magnum position of mammals is
convergent with that in birds, but the foramen magnum position of
Caudipteryx is homologous. I guess so. I dunno.
> >> You must instead understand that it is "missing data" for all, not most,
> >> theropods. It is also "missing data" for all pterosaurs. All known
> >> theropods and pterosaurs lack wing feathers.
> >
> >You must understand what "missing data" means. It doesn't mean you score
> >the animal as lacking that state. It means you can't score that animal at
> >all, as either having or lacking the state. Sorry.
>
> It means that all pterosaurs and theropods are missing wing feathers. If
> you assume that theropods have wing feathers, you are taking an
> unusually big leap of faith for a scientist, but a routine leap for many
> cladistic palontologists who support the bird-theropod link.
Sorry, but I'm only assuming that I can't tell, most of the time, whether
they have "wing feathers".
> In any case,
> this is evidence that Caudipteryx is a bird, but of course those who argue
> that it is not a bird will simply ignore such evidence.
You continue to misunderstand the concept of missing data. Until you
understand it, we won't get anywhere.
> >> That does not answer my question. Why did Sereno omit this character
if it
> >> is in fact present in some oviraptorosaurs?
> >
> >Sereno omitted the character (I suppose, not being able to read minds)
> >because he didn't notice it,
>
> Or perhaps because he did not think that oviraptorosaurs have a
> posteroventral foramen magnum.
No, that wouldn't be a reason. He didn't include *only* characters that
matched his particular phylogeny, but all the scorable characters he could
find.
> > or because he didn't think it was possible to
> >score reliably, or some other reason I haven't thought of. Characters tend
> >to accumulate over time, because people notice features that weren't
> >noticed before. It's considered kosher to use characters people have used
> >in previous analyses, or else to explain why you didn't. Since Feduccia's
> >"analysis" came after Sereno's, the question is why Feduccia didn't use
> >Sereno's characters.
>
> That does not matter. He claims that the characters used in the original
> analysis by Ji et al. are either symplesiomorphies or they are not
> verifiable on the fragmentary skull of Caudipteryx. Since symplesiomorphs
> are useless in ascertaining branching order, he did not use the characters
> that some cladists used.
1. That claim isn't backed up by any mention of the distribution of
characters in the relevant taxa. 2. We were talking about Sereno 1999, not
Ji et al.
> >> Don't understand your point at all. Birds have shortened tails and thus
> >> their caudofemoralis is reduced. Theropods do not have shortened tails;
> >> they have a more massive caudofemoralis. That shows Caudipteryx is more
> >> birdlike than theropodlike. Why do we "downweight" this character, unless
> >> one wants to de-emphasize the birdlike characters of Caudipteryx so that
> >> one can claim it is not a bird?
> >
> >Because it's considered bad form to score the same thing twice.
>
> Caudofemoralis and short tail are different things.
>
> >If you
> >have used "short tail" as a character, using "reduced caudofemoralis" is
> >just another way to say the same thing.
>
> You are arguing for character non-independence.
Bingo.
> By ignoring some
> characters because they are missing in theropods,
Again you refuse to understand the concept of "missing data".
> ignoring some because
> they are avian autapomorphies,
You also appear not to understand the concept of "autapomorphy".
> and finally ignoring others because they are
> supposedly part of a suite,
Aren't you the person who was claiming that adaptive characters weren't
useful in determining phylogeny?
> you have managed to ignore practically all of
> the avian characters of Caudipteryx! No wonder you can argue that it is
> not a bird. If I ignore all the reptilian characters of the fence lizard,
> I can call it an amphibian too.
I notice you have no specific defenses of any of these characters.
> > You are pretending to have twice
> >as much evidence as you really do have. (Assuming you agree that one is a
> >consequence of the other.)
>
> Actually I have no evidence at all according to you since all of the
> evidence can be ignored.
Again, no response to the difficulties I actually mentioned.
> >> How about the reversed hallux? Would that be a strong avian character?
>
> >Better. At least one might hope to score it. Does Caudipteryx have a
> >reversed hallux?
>
> Yes, but you can ignore this one as well because it is an avian
> autapomorphy.
You are confused. Calm down a bit and read this stuff again.
> >> >I think Cal might be in the process of turning Microraptor into a bird. If
> >> >so, this creates problems of character distribution all its own, probably
> >> >more than it solves for him. The presence of *serrated*, waisted teeth,
> >> >for example.
> >>
> >> I am not turning it into anything. I merely point out that it is not
> >> positively identified as either a bird or a theropod.
> >
> >Why? It would seem to be an easy thing to do, considering the giant
> >morphological gap between the two. Or so you would say. Why can't you do
> >it yourself?
>
> Partly because it is not as well preserved as some other fossils from the
> same locality, and partly because there may be observational mistakes. For
> example, they claim that Microraptor has a sickle claw. This is not
> verifiable based on their drawing.
I was able to verify it easily. Look again. Try measuring.
> They also claim that the teeth are
> serrated, but no actual photograph was presented. Hence it is prudent to
> wait until other experts have had the chance to look at it before we
> uncritically accept the author's opinions.
There are some people whose opinions you accept uncritically. Do I detect
a bias?
> >> It is an adaptive character. Adaptive characters often evolve
> >> independently in different lineages.
> >
> >You are saying that clavicles have been lost and regained many times in
> >theropods? Wouldn't that contradict Dollo's law?
>
> I am not saying that. You are.
No, I'm not saying that at all. I'm saying that clavicles often are not
preserved. Please explain the distribution of known clavicles/furculae in
theropods without invoking either a) non-preservation or b) massive loss
and re-evolution, both of which you seem to have rejected as possible
explanations.
> >> >> >Caudipteryx has a clear boot.
> >> >>
> >> >> Have you seen the actual specimen?
> >> >
> >> >Yes. Have you?
> >>
> >> No I have not seen it. But since you had claimed that Protarchaeopteryx
> >> had serrated teeth and then backed away from that claim, your observations
> >> are less reliable than those of Feduccia. I believe Feduccia's claim that
> >> Caudipteryx does not have a theropod style pubic boot.
> >
> >Then why did you ask if I had seen it?
>
> That is because the end of the pubis is obscured by rock in the
> illustrations accompanying the paper. Perhaps more rock has since been
> removed.
>
> >> >> What about acetabulum not theropod-like? Can we ignore that also?
> >> >
> >> >Could you score that for a new taxon? Needs a better description.
> >>
> >> That means you are ignoring yet another character that shows
Caudipteryx is
> >> not a theropod.
> >
> >It's not a character until you define it to the point where we can tell if
> >an animal has it or not.
>
> That means you cannot tell whether Caudipteryx has it or not. Then you
> have no data to dispute Feduccia's observation.
If you are indeed advocating that we just believe whatever Feduccia says,
and forget about evidence, fine. If we should actually demand evidence,
then we have to be able to tell what he means by "acetabulum not
theropod-like".
> >> >> No theropod has any gizzard stones. The only "theropod" that does is
> >> >> Caudipteryx.
> >>
> >> >Like I said, an autapomorphy, and not informative.
> >>
> >> Yes, all of the birdlike characters in Caudipteryx are avian
> >> autapomorphies.
> >
> >You should look up the definition of autapomorphy. In this case, any
> >characters Caudipteryx shares with birds are synapomorphies, not
> >autapomorphies. But gizzard stones can't be such a character, since they
> >are unknown for fossil birds (actually, I don't know of any; do you?).
>
> Gizzard stones are well known in living birds.
>
> >Unless you are claiming that Caudipteryx is a highly derived bird, sister
> >taxon to some bird that does have known gizzard stones, it's either
> >convergent between Caudipteryx and that bird, or gizzard stones happened
> >never to be preserved in all intervening birds. That's missing data
> >(remember?), and hence uninformative.
>
> The use of gizzard stones is convergent between Caudipteryx and other
> living birds, yes. But since no known theropod has gizzard stones, it is
> one more fact arguing against the identity of Caudipteryx as a theropod.
Sorry, but that makes it an autapomorphy of Caudipteryx. Autapomorphies
are not informative. Suppose I were to claim that whales weren't mammals,
because no known mammal (other than a whale, that is) lacks legs; and
there are of course numerous other profound diffrences between whales and
mammals (other mammals). Would that make any sense? It's the same with
Caudipteryx. Gizzard stones are a unique, evolved feature that don't
prevent it from being a theropod.
> >> But they are informative if one is trying to figure out
> >> what kind of beast it was. The misidentification of Caudipteryx is thus
> >> yet another example of the weakness of cladistic methodology.
> >
> >No, they are not informative. As I have explained. What you are saying is
> >that some birds have gizzard stones, Caudipteryx has gizzard stones,
> >therefore Caudipteryx is a bird. For this to work, there would have to be
> >some clade of birds for which gizzard stones were a synapomorphy, and
> >Caudipteryx would have to belong to that clade. You can't define such a
> >clade. And of course there are convergences in evolution of gizzard stones
> >within dinosaurs, so it's a useless character anyway by your standards.
>
> Gizzard stones is not a taxonomic character, I agree.
Despite the fact that you have been claiming it is?
> However, it is
> important to remember that phylogeny cannot be directly observed, but must
> be inferred, and often from facts that are not directly phylogenetic (G.G.
> Simpson 1984). Hence it is not a good idea to ignore such important facts
> as the presence of gizzard stones, because it is consistent with a
> vegetarian diet and because it is inconsistent with the claim that
> Caudipteryx is a theropod, since theropods are carnivores with serrated
> teeth.
Essentialist thinking. Most theropods are carnivores, but there is nothing
preventing some theropods from adopting a different lifestyle. After all,
the primitive dinosaur was a carnivore too (rather like a theropod in
basic anatomy), but still there are sauropods and ornithischians.
Therizinosaurs are another group of likely herbivorous theropods. Are you
actually claiming that it's impossible or highly unlikely for any theropod
to have changed diet?
> >> >I could say that Caudipteryx has a theropod-like femur, and call that a
> >> >character. How would you refute me? I haven't told you what
> >> >"theropod-like" means. Same for these characters. Explain them adequately
> >> >for scoring, or they must be ignored.
> >>
> >> If you want to claim that, then go ahead and do so. It is your
> >> prerogative.
> >
> >No counterargument?
>
> None is necessary.
!
AM Yates
On Sun, 4 Feb 2001, John Harshman wrote:
>
<Cal > No theropod has any gizzard stones. The only "theropod" that
does is
> > >> >> Caudipteryx.
Cal is dead wrong here. Check out "Kobayashi et. al. 1999. Herbivorous
diet in an ornithomimid
dinosaur. Nature 402, 480 -481". These dinosaurs have clear gastrolith
masses.
>
<Cal again > However, it is
> > important to remember that phylogeny cannot be directly observed, but must
> > be inferred, and often from facts that are not directly phylogenetic (G.G.
> > Simpson 1984). Hence it is not a good idea to ignore such important facts
> > as the presence of gizzard stones, because it is consistent with a
> > vegetarian diet and because it is inconsistent with the claim that
> > Caudipteryx is a theropod, since theropods are carnivores with serrated
> > teeth.
>
< John> Essentialist thinking. Most theropods are carnivores, but there
is nothing
> preventing some theropods from adopting a different lifestyle. After all,
> the primitive dinosaur was a carnivore too (rather like a theropod in
> basic anatomy), but still there are sauropods and ornithischians.
> Therizinosaurs are another group of likely herbivorous theropods. Are you
> actually claiming that it's impossible or highly unlikely for any theropod
> to have changed diet?
Ironically there is very good evidence that several theropods (non avian
that is) did. These include Theriznosaurs, Oviraptorosaurs and
Ornithomimosaurs. The evidence is strongest for Ornithomimosaurs, Cal
should really check out the paper I cited before making anymore
pronouncements about theropod herbivory and gastroliths. I wonder what
line he will take to worm out of this one!
cheers
Adam Yates
bull.net Cal King
>
>
>On Sun, 4 Feb 2001, John Harshman wrote:
>
>
>>
><Cal > No theropod has any gizzard stones. The only "theropod" that
>does is
>> > >> >> Caudipteryx.
>
>Cal is dead wrong here. Check out "Kobayashi et. al. 1999. Herbivorous
>diet in an ornithomimid
>dinosaur. Nature 402, 480 -481". These dinosaurs have clear gastrolith
>masses.
>Ironically there is very good evidence that several theropods (non avian
>that is) did. These include Theriznosaurs, Oviraptorosaurs and
>Ornithomimosaurs. The evidence is strongest for Ornithomimosaurs,
Here you seem to be less certain about the evidence than in your opening
remark. Do ornithomimids in fact have gizzard stones? How strong is the
evidence in your opinion?
> Cal
>should really check out the paper I cited before making anymore
>pronouncements about theropod herbivory and gastroliths. I wonder what
>line he will take to worm out of this one!
>
>cheers
>
>Adam Yates
As Harshman pointed out, gizzard stones is a convergence. I also pointed
out that it is not a taxonomic character, but it does reveal facts about
diet and thus taxonomic affinity. I don't think that you are suggesting
that the ornithomimids are more closely related to the birds than the
dromaeosaurs because of the gizzard stones are you? Besides, there are
lots of other uniquely avian characters Cauditperyx has, and the cladists
are "worming" their way out of having to confront that evidence.
More comments after I have read the paper you cited.
bull.net Cal King
<harshman.diespamdi...@user-2iveku7.dialup.mindspring.com>,
>In article <_9of6.11373$vh.4...@bgtnsc05-news.ops.worldnet.att.net>,
>getulus@no bull.net (Cal King) wrote:
>> That is a strawman argument because I have said that even though the three
>> fingered hand is not a synapomorphy between birds and theropods, it can
>> still be used in theropod phylogeny since some theropods have fewer, and
>> some more than, 3 fingers.
>
>I forgot that you have a magic method of telling in advance which
>characters converge, and how often, without resorting to any phylogeny.
No magic method, we simply use comparative anatomy, developmental data,
molecular distance data, or even biogeographic analysis. In fact, any
scrap of evidence we can find. But it is not infallible, although it is
certainly better than employing circular argument of the supposed
synapomorphs supporting mononphyly and the monophyly supporting
synapomorphy of the supposed synapomorphs.
>It's of course obvious that the foramen magnum position of mammals is
>convergent with that in birds, but the foramen magnum position of
>Caudipteryx is homologous. I guess so. I dunno.
Who is claiming that Caudipteryx is a mammal? Fact is that theropods do
not have a posteroventral foramen magnum. So this character, along with
others that theropods do not have but that birds do, show that it is in
fact a bird.
>> It means that all pterosaurs and theropods are missing wing feathers. If
>> you assume that theropods have wing feathers, you are taking an
>> unusually big leap of faith for a scientist, but a routine leap for many
>> cladistic palontologists who support the bird-theropod link.
>
>Sorry, but I'm only assuming that I can't tell, most of the time, whether
>they have "wing feathers".
Then you admit you have no evidence of wing feathers in theropods or
pterosaurs? That is not a valid reason for excluding the fact that
Caudipteryx has wing feathers from the analysis.
>> In any case,
>> this is evidence that Caudipteryx is a bird, but of course those who argue
>> that it is not a bird will simply ignore such evidence.
>
>You continue to misunderstand the concept of missing data. Until you
>understand it, we won't get anywhere.
The cladists' analysis is surely missing data; it is missing the uniquely
avian characters of Caudipteryx. Do you understand the importance of
missing data?
>> >> That does not answer my question. Why did Sereno omit this character
>if it
>> >> is in fact present in some oviraptorosaurs?
>> >
>> >Sereno omitted the character (I suppose, not being able to read minds)
>> >because he didn't notice it,
>>
>> Or perhaps because he did not think that oviraptorosaurs have a
>> posteroventral foramen magnum.
>
>No, that wouldn't be a reason. He didn't include *only* characters that
>matched his particular phylogeny, but all the scorable characters he could
>find.
And you said you cannot read minds?
>> That does not matter. He claims that the characters used in the original
>> analysis by Ji et al. are either symplesiomorphies or they are not
>> verifiable on the fragmentary skull of Caudipteryx. Since symplesiomorphs
>> are useless in ascertaining branching order, he did not use the characters
>> that some cladists used.
>
>1. That claim isn't backed up by any mention of the distribution of
>characters in the relevant taxa. 2. We were talking about Sereno 1999, not
>Ji et al.
We are talking about the characters found in Caudipteryx. Are you
suggesting that Ji et al. saw an entirely different character set than
Sereno?
>> You are arguing for character non-independence.
>
>Bingo.
Show me some evidence. For example, the horned lizard (Phrynosoma) has a
short tail. Do you know if it in fact has reduced caudofemoralis? Or can
you give me some other examples that short tails are invariably associated
with reduced caudofemoralis?
>> By ignoring some
>> characters because they are missing in theropods,
>Again you refuse to understand the concept of "missing data".
If one ignores character evidence, one's analysis is surely missing data.
Unless one has all the facts, one is not going to reach a correct answer.
The cladists' analyses are missing some important facts; that is why they
don't have the correct answer.
>> ignoring some because
>> they are avian autapomorphies,
>
>You also appear not to understand the concept of "autapomorphy".
Autapomorphy in the present context is an excuse to ignore the avian
characters of Caudipteryx.
>> and finally ignoring others because they are
>> supposedly part of a suite,
>
>Aren't you the person who was claiming that adaptive characters weren't
>useful in determining phylogeny?
Yes, and that is why the bird-dinosaur link is untenable, because it is
based on adaptive characters.
>> you have managed to ignore practically all of
>> the avian characters of Caudipteryx! No wonder you can argue that it is
>> not a bird. If I ignore all the reptilian characters of the fence lizard,
>> I can call it an amphibian too.
>
>I notice you have no specific defenses of any of these characters.
I notice that you simply ignore them.
>> Actually I have no evidence at all according to you since all of the
>> evidence can be ignored.
>
>Again, no response to the difficulties I actually mentioned.
You mean because we have "difficulty" telling whether theropods or
pterosaurs actually have wing feathers, we should therefore ignore this
character even though it is found in Caudipteryx? One way to get around
this kind of "difficulty" is to admit that these "difficulties" does not
make any difference.
>> >> How about the reversed hallux? Would that be a strong avian character?
>>
>> >Better. At least one might hope to score it. Does Caudipteryx have a
>> >reversed hallux?
>>
>> Yes, but you can ignore this one as well because it is an avian
>> autapomorphy.
>
>You are confused. Calm down a bit and read this stuff again.
Okay. Caudipteryx has wing feathers, a posteroventral foramen magnum, and
a reversed hallux. Why is it not a bird?
>There are some people whose opinions you accept uncritically. Do I detect
>a bias?
That is nonsense.
>No, I'm not saying that at all. I'm saying that clavicles often are not
>preserved. Please explain the distribution of known clavicles/furculae in
>theropods without invoking either a) non-preservation or b) massive loss
>and re-evolution, both of which you seem to have rejected as possible
>explanations.
Loss of the clavicles is massive. Many flightless birds have "clavicular
splints" even though their volant ancestors have the furcula.
>> That means you cannot tell whether Caudipteryx has it or not. Then you
>> have no data to dispute Feduccia's observation.
>
>If you are indeed advocating that we just believe whatever Feduccia says,
No, but you are simply ignoring what he says without any evidence to refute
him. OTOH, what he says is based on evidence. I believe in evidence.
>and forget about evidence, fine. If we should actually demand evidence,
>then we have to be able to tell what he means by "acetabulum not
>theropod-like".
It is not theropod-like. Do you have contradictory evidence?
>> The use of gizzard stones is convergent between Caudipteryx and other
>> living birds, yes. But since no known theropod has gizzard stones, it is
>> one more fact arguing against the identity of Caudipteryx as a theropod.
>
>Sorry, but that makes it an autapomorphy of Caudipteryx. Autapomorphies
>are not informative.
Then the cladists are uninformed of the avian characters of Caudipteryx.
No wonder they couldn't tell it is a bird.
>Suppose I were to claim that whales weren't mammals,
>because no known mammal (other than a whale, that is) lacks legs;
Please come up with a better example. The manatee lacks hindlegs.
> and
>there are of course numerous other profound diffrences between whales and
>mammals (other mammals).
Darwin points out that whales converge upon fish. That is one reason why
we should not rely on superficial similarities, no matter how large a set
it is (e.g. convergences between whales and manatees). That is why I
reject your use of "congruence with other characters." Because such a
method can be fooled by large numbers of convergences, such as those
between whales and manatee or between whales and fish.
>Would that make any sense? It's the same with
>Caudipteryx. Gizzard stones are a unique, evolved feature that don't
>prevent it from being a theropod.
Not in and of itself. But there are plenty of characters not found in
theropods but only in birds. Together they constitute excellent evidence
that Caudipteryx is a bird. But the cladists choose to ignore these facts.
Too bad.
>> Gizzard stones is not a taxonomic character, I agree.
>
>Despite the fact that you have been claiming it is?
No, you misunderstood. Facts that help us infer phylogeny are not
necessarily taxonomic characters, e.g. stratigraphy, biogeography. See
comment below:
bull.net Cal King
-100...@eis.bris.ac.uk>:
>Cal is dead wrong here. Check out "Kobayashi et. al. 1999. Herbivorous
>diet in an ornithomimid
>dinosaur. Nature 402, 480 -481". These dinosaurs have clear gastrolith
>masses.
I checked the paper out. These dinosaurs had grains of sand inside their
bodies. The grain size for the "gastrolith" of a single juvenile is
measured, and the average size of these grains of sand is well below the
range of modern herbivorous birds with a similar body weight. Only when the
smallest grains are excluded does the average grain size approach that of
modern birds. We don't know why these dinosaurs had sand in their bodies,
but it would be wishful thinking to suggest that these grains of sand were
gizzard "stones." It is also a leap to suggest these dinosaurs were
herbivorous.
Evan Robinson
the oviraptor could be descended from a proto-bird also. Although many
authors believe that Caudopteryx is a bird, no one has suggested it for
oviraptor. Some of this you have probably already addressed with Cal,
but I can't read that yet, so you could ignore redundant points.
> > harshman....@sjm.infi.net (John Harshman) wrote:
> > You should list the birdlike characters. We'll see how they go.
>
> I'll bite. Here are some of Feduccia's arguments that Caudiptteryx is
> a flightless bird, and then I have a challenge afterwards:
>
> Caudipteryx and Protoarchaeopteryx are replete with features of
> secondarily flightless Mesozoic sauriurine birds (Feduccia, 1999)
> including:
>
> A short tail, similar to that of Confuciusornis, with some fusion of
> the vertebrae and therefore a quasi-pygostyle.
> Many derived theropods have shortened tails. Better score this
> character for them too and see what happens.
Which theropods? Here’s a few standards:
Sinosauopteryx 63 Caudials
Deinonuchus 36-40 Caudials
Oviraptoroids 30 Caudials
Protoarcheopteryx 28 Caudials
Archeopteryx 22 Caudials
Caudipteryx 22 Caudials
From Qiang et al, Nature 1998 (1): “The tail of (Caudipteryx) is
articulated and well preserved, and includes 22 vertebrae, as in
Archaeopteryx. It is shorter than the 30 segment tails of oviraptorids.
Most other non-avian theropods have much longer tails”.
> > Secondarily reduced wing feathers that attach to its hands in the
> > same manner as flighted birds such as Confuciusornis, locking up
> > it’s hand for any type of predatory function.
> No preservation of such structures in most taxa, so it would have to
> be scored as missing data in most of the matrix.
This one does it for me. Do you really think that there is a reason to
have wings, that attach to your hands, unless you ancestors were flying
birds? I can’t possibly buy into pictures of Caudapteryx having wings
to catch bugs. No meat eating dinosaur would be able to function with
this problem. Most other raptors, except for maybe oviraptors and maybe
ostrich mimics were meat eaters.
> > Birdlike skull with a posteroventral foramen magnum. In theropods,
> > foramen magnum is posterior and the neck enters the skull from
> > behind.
> Potentially one character, although he should be careful to score
> other oviraptorosaurs too. (Apparently, "posteroventral foramen
> magnum" is the only scorable feature of the skull that makes it
> birdlike. Rather an overstatement, wouldn't you think?)
I would not debate this, because I am arguing that the oviraptor has a
bird-like skull also. It has what looks like an enlarged front brain
and cerebellum, and except for egg-teeth, it has a beak.
> > The middle and third metatarsal is longer than the outer two, a
> > distinctive avian feature.
> Interesting character. I don't have enough good illustrations to tell
> what the condition is in any other derived theropods, particularly
> oviraptorosaurs.
In Velociraptors mongoliensis, metetarsal 4 is longer than metatarsal
2.
From a "Late Cretaceous Oviraptor..." (Clark et al 1999): “The proximal
end of the third metacarpal is well developed rather than being reduced
as in some (other) oviraptorids.” I think this means that some do and
some don't although I can't find a good write up.
> > No furcula, common in flightless birds.
> Furculae are very commonly not preserved. Check out the known
> distribution within theropods and see what I mean.
According to Nature (Qiang et al 1998), regarding Protoarcheopteryx, to
whom Feduccia’s comments are also applying: “the clavicals are fused
into a broad, U-shaped furcula (interclavicular angle is abot 60
degrees as in Archaeopteryx, Confuciusornis and many non-avian
theropods.” Oviraptor has a large furcula. This character is probably
too debateable and I agree that we should probably throw it out.
> > Eats it’s food with gizzard stones.
> Seems to be an autapomorphy, as far as I can tell. Unless you know of
> any gizzard stones for Archaeopteryx.
Just further proof that it is a vegetarian, and has a bird digestive
system. Moas and our pet bird eat with gizzard stones.
> Extensive suite of cursorial-bird-like locomotory characters (Jones et
> al).
> Too vague to score, and inferred from the actual anatomical
> characters, which it would be better to score.
O.K. Sorry, “The avian center of mass is far from the pelvis, to
compensate running birds run with the femur subhorizontally. … bipedal
dinosaurs have a center of mass near the hipjoint and rotate the the
entire hindlimb.”
There is no reason for a theropod to change it’s center of mass more
forward unless for balance in flight. Characters:
Tibiotarsus + tarsometarsus in birds = femur + tibia + metatarsal III
in theropods.
Total hind limb length in cursial birds is one and a half times longer
than theropods and ornithopods
Tibia plus metatarsal in Caudipteryx equals effective limb length in
birds=total hindlimb length in theropods.
Center of mass 2.3 times more anterior than in deinonychus.
Another part of the point is that if you hang Archeopteryx from a rope
across his back, his arms and legs are about the same length. This is
not true of Velioceraptors. Nature again, regarding Caudipteryx(1):
“Compared to the humerus, forearm length is similar to that in
oviraptorosaurs, Archeopteryx and Protoarcheopteryx”. Thus Caudipteryx
and oviraptors are similar to birds, separate from all other theropods.
What evidence is there that Caudipteryx did not descend from a volant
bird? I have found only this, from Sereno (1999): Given the absence of
basic flight related features in it’s skeleton (such as a laterally
facing glenoid), there is no evidence of flight function in the
ancestory of Caudipteryx”.
My reprint is poor, but I believe that it ( Science Vol 279, 20 March
1998, pg: 1917) says, regarding Rahona ostromi, a bird, : “The scapula
of Rahona is probably positioned dorsally on the ribcage rather than
ventrally as in theropods, resulting in a more laterally directed
glenoid fossa.”
> > Prove that Oviraptor did NOT descend from a
> > Jurassic bird.
> Operationally, how would this be done? If other oviraptorosaurs are
> allowed to be birds too, why not other maniraptorans? Can we even
> test this on a well-resolved phylogeny?
Your right, it can’t be done. I was being unfair. I believe that
Caudopteryx is a flightless bird, particularly because of it’s wings
and feathers. If it is closely related to oviraptor, then I wondered,
how do we know that the oviraptor is not a bird? But if you do not
believe that Caudopteryx is a bird, then it will be even harder for me
to prove.
> 4)The oviraptor is the only dinosaur proven to have ratite-ornithoid
> shelled eggs.
What exactly does that mean?
3 Oviraptors have been found laying on nest. Embryo’s attributed to
these Oviraptor‘s have been found in two separate nests.
These eggs have an ornithoid-basic shell type (often called ornithoid-
ratite) as they are similar to ratite eggshells. These eggs are called
Elongatoolithidae. The mammiliary layer and the outer continous layer
are distinctly separate and are possibly indicative of a more avian
reproductive tract. Although there are good reasons to have a
convergent eggshell (ie special layers can be added for microbal
protection and coloring), this shell has been used by Norell and others
to say that bird eggs evolved from dinosaur eggs. However, thus far
the oviraptor is the only dinosaur proven to have this shell type.
Troodon, for example, has a prismatic egg, which is more reptilian.
This same egg type has recently been found in Mid-cretaceous North
America and has been attributed to Microvenator based solely on it’s
relationship to oviraptor. I was suggesting that as it has a bird-like
egg shell, that it could have descended from a bird.
Thanks,
Evan Robinson
Quiang G, P Currie, M Norell, and Ji Shu-An. Two feathered Dinosaurs
from Northeastern China". Nature Vol 395. 25 June 1998.pg 753
White Shite
>the oviraptor could be descended from a proto-bird also. Although many
>authors believe that Caudopteryx is a bird,
Few see this theropod as Aves but it is a "bird" in the sense of feathered
reptile.
no one has suggested it for
>oviraptor.
It has.
>Which theropods? Here’s a few standards:
>
>Sinosauopteryx 63 Caudials
>Deinonuchus 36-40 Caudials
>Oviraptoroids 30 Caudials
>Protoarcheopteryx 28 Caudials
>Archeopteryx 22 Caudials
>Caudipteryx 22 Caudials
Try a therizinosaur or alvarezsaur. More shortened tails.
>This one does it for me. Do you really think that there is a reason to
>have wings, that attach to your hands, unless you ancestors were flying
>birds?
Not true feathers, but that still does not change that this is currently not
a testable character for most theropods. Although it is proven that feathers
(and, in my opinion, flight) are a synapomorphic feature of
Caudipteryx+Neornithes.
I can’t possibly buy into pictures of Caudapteryx having wings
>to catch bugs. No meat eating dinosaur would be able to function with
>this problem.
I prefer a theory that lets us compare extant animals to the hypothesized
ancestral form to test how viable it is (I don't see any gliders that don't
climb or gigantothermic land animals)..
>Just further proof that it is a vegetarian, and has a bird digestive
>system. Moas and our pet bird eat with gizzard stones.
Are they homologous?
>“The avian center of mass is far from the pelvis, to
>compensate running birds run with the femur subhorizontally. … bipedal
>dinosaurs have a center of mass near the hipjoint and rotate the the
>entire hindlimb.”
>There is no reason for a theropod to change it’s center of mass more
>forward unless for balance in flight.
Or for some other reason which involves reduction of the tail.
>Your right, it can’t be done. I was being unfair. I believe that
>Caudopteryx is a flightless bird, particularly because of it’s wings
>and feathers. If it is closely related to oviraptor, then I wondered,
>how do we know that the oviraptor is not a bird? But if you do not
>believe that Caudopteryx is a bird, then it will be even harder for me
>to prove.
Depends on what you mean by bird. If you mean feathered animal, then
Caudipteryx (and by inference the rest of the oviraptorosaur and
therizinosaur group as well as nonavian Eumaniraptora) is a bird. If you
mean is Caudipteryx within Aves then no.
>Troodon, for example, has a prismatic egg, which is more reptilian.
You mean that it is comparatively less derived. All dinosaurs are Reptilia.
White Shite
var...@cableinet.co.uk
ICQ 88954483
John Harshman
<theeg...@my-deja.com> wrote:
Note that Oviraptoroids have shorter tails than any other taxa except the
last two. Note that all the derived theropods have shorter tails than the
primitive Sinosauropteryx. Archaeopteryx and Caudipteryx are just extreme
ends of a long-term trend. This character does put Caudipteryx and
Archaeopteryx together, but it also should attract Caudipteryx to
oviraptor, to a lesser extent.
> > > Secondarily reduced wing feathers that attach to its hands in the
> > > same manner as flighted birds such as Confuciusornis, locking up
> > > it’s hand for any type of predatory function.
>
> > No preservation of such structures in most taxa, so it would have to
> > be scored as missing data in most of the matrix.
>
> This one does it for me. Do you really think that there is a reason to
> have wings, that attach to your hands, unless you ancestors were flying
> birds? I can’t possibly buy into pictures of Caudapteryx having wings
> to catch bugs. No meat eating dinosaur would be able to function with
> this problem. Most other raptors, except for maybe oviraptors and maybe
> ostrich mimics were meat eaters.
I'm hesitant to make claims about what could or couldn't have been
functional in the absence of evidence. We don't know what the integument
around the hands of most theropods looked like.
> > > Birdlike skull with a posteroventral foramen magnum. In theropods,
> > > foramen magnum is posterior and the neck enters the skull from
> > > behind.
>
> > Potentially one character, although he should be careful to score
> > other oviraptorosaurs too. (Apparently, "posteroventral foramen
> > magnum" is the only scorable feature of the skull that makes it
> > birdlike. Rather an overstatement, wouldn't you think?)
>
> I would not debate this, because I am arguing that the oviraptor has a
> bird-like skull also. It has what looks like an enlarged front brain
> and cerebellum, and except for egg-teeth, it has a beak.
All potentially scorable characters.
> > > The middle and third metatarsal is longer than the outer two, a
> > > distinctive avian feature.
>
> > Interesting character. I don't have enough good illustrations to tell
> > what the condition is in any other derived theropods, particularly
> > oviraptorosaurs.
>
> In Velociraptors mongoliensis, metetarsal 4 is longer than metatarsal
> 2.
>
> From a "Late Cretaceous Oviraptor..." (Clark et al 1999): “The proximal
> end of the third metacarpal is well developed rather than being reduced
> as in some (other) oviraptorids.” I think this means that some do and
> some don't although I can't find a good write up.
Whoops, that last was a metacarpal, not a metatarsal. But at least we can
score Velociraptor as lacking this state.
> > > No furcula, common in flightless birds.
>
> > Furculae are very commonly not preserved. Check out the known
> > distribution within theropods and see what I mean.
>
> According to Nature (Qiang et al 1998), regarding Protoarcheopteryx, to
> whom Feduccia’s comments are also applying: “the clavicals are fused
> into a broad, U-shaped furcula (interclavicular angle is abot 60
> degrees as in Archaeopteryx, Confuciusornis and many non-avian
> theropods.” Oviraptor has a large furcula. This character is probably
> too debateable and I agree that we should probably throw it out.
>
> > > Eats it’s food with gizzard stones.
>
> > Seems to be an autapomorphy, as far as I can tell. Unless you know of
> > any gizzard stones for Archaeopteryx.
>
> Just further proof that it is a vegetarian, and has a bird digestive
> system. Moas and our pet bird eat with gizzard stones.
I think it's an extreme leap from "is a vegetarian" to "has a bird
digestive system". It looks to me as if the primitive bird (approximated
by Archaeopteryx) is a carnivore/insectivore, so vegetarianism isn't a
synapomorphy of birds. The birds you are talking about are separated from
Caudipteryx by many nodes filled with non-herbivores. Herbivory just isn't
a character that unites Caudipteryx with birds. It's an autapomorphy,
wherever Caudipteryx is placed.
> > Extensive suite of cursorial-bird-like locomotory characters (Jones et
> > al).
>
> > Too vague to score, and inferred from the actual anatomical
> > characters, which it would be better to score.
>
> O.K. Sorry, “The avian center of mass is far from the pelvis, to
> compensate running birds run with the femur subhorizontally. … bipedal
> dinosaurs have a center of mass near the hipjoint and rotate the the
> entire hindlimb.”
You are approaching closer to anatomical characters. I suggest using the
length of the femur compared to the length of the tibia/tibiotarsus.
> There is no reason for a theropod to change it’s center of mass more
> forward unless for balance in flight.
That's just a lack of imagination. We don't know what's driving this
change. Perhaps there was some selective advantage to a really short tail,
and the short tail forced everything else.
> Characters:
>
> Tibiotarsus + tarsometarsus in birds = femur + tibia + metatarsal III
> in theropods.
>
> Total hind limb length in cursial birds is one and a half times longer
> than theropods and ornithopods
>
> Tibia plus metatarsal in Caudipteryx equals effective limb length in
> birds=total hindlimb length in theropods.
>
> Center of mass 2.3 times more anterior than in deinonychus.
>
> Another part of the point is that if you hang Archeopteryx from a rope
> across his back, his arms and legs are about the same length. This is
> not true of Velioceraptors. Nature again, regarding Caudipteryx(1):
> “Compared to the humerus, forearm length is similar to that in
> oviraptorosaurs, Archeopteryx and Protoarcheopteryx”. Thus Caudipteryx
> and oviraptors are similar to birds, separate from all other theropods.
These are approaching the level of useable characters, but they need
better definitions. I am also concerned that some of these characters are
simply restatements of the same thing. Still, try them out. Add them to
Sereno's (1999) matrix and see what happens. You also need to score them
for other oviraptorosaurs (and all the other theropods that Jones et al.
left out). I would also check out Microraptor.
> What evidence is there that Caudipteryx did not descend from a volant
> bird? I have found only this, from Sereno (1999): Given the absence of
> basic flight related features in it’s skeleton (such as a laterally
> facing glenoid), there is no evidence of flight function in the
> ancestory of Caudipteryx”.
Another bit of evidence is the tree. If Caudipteryx is a bird, and
Archaeopteryx is a bird, then according to the tree so is Velociraptor,
troodontids, and various other maniraptorans, at least. This would show
most of the bird characters you mention to be convergences, or secondary
losses in those other maniraptorans. You are of course free to change the
tree, but that too would involve a great amount of homoplasy.
> My reprint is poor, but I believe that it ( Science Vol 279, 20 March
> 1998, pg: 1917) says, regarding Rahona ostromi, a bird, : “The scapula
> of Rahona is probably positioned dorsally on the ribcage rather than
> ventrally as in theropods, resulting in a more laterally directed
> glenoid fossa.”
I don't think Rahonavis is considered a bird by most systematists,
although it generally comes out very close to birds.
> > > Prove that Oviraptor did NOT descend from a
> > > Jurassic bird.
>
> > Operationally, how would this be done? If other oviraptorosaurs are
> > allowed to be birds too, why not other maniraptorans? Can we even
> > test this on a well-resolved phylogeny?
>
> Your right, it can’t be done. I was being unfair. I believe that
> Caudopteryx is a flightless bird, particularly because of it’s wings
> and feathers. If it is closely related to oviraptor, then I wondered,
> how do we know that the oviraptor is not a bird? But if you do not
> believe that Caudopteryx is a bird, then it will be even harder for me
> to prove.
What I'm saying is that we need either a phylogeny that makes the animals
we think are birds monophyletic, or we need to have some of the animals we
think aren't birds into birds too. That raises the question of what
evidence would prove that an animal is not descended from a flying bird.
> > 4)The oviraptor is the only dinosaur proven to have ratite-ornithoid
> > shelled eggs.
>
> What exactly does that mean?
>
> 3 Oviraptors have been found laying on nest. Embryo’s attributed to
> these Oviraptor‘s have been found in two separate nests.
> These eggs have an ornithoid-basic shell type (often called ornithoid-
> ratite) as they are similar to ratite eggshells. These eggs are called
> Elongatoolithidae. The mammiliary layer and the outer continous layer
> are distinctly separate and are possibly indicative of a more avian
> reproductive tract. Although there are good reasons to have a
> convergent eggshell (ie special layers can be added for microbal
> protection and coloring), this shell has been used by Norell and others
> to say that bird eggs evolved from dinosaur eggs. However, thus far
> the oviraptor is the only dinosaur proven to have this shell type.
> Troodon, for example, has a prismatic egg, which is more reptilian.
> This same egg type has recently been found in Mid-cretaceous North
> America and has been attributed to Microvenator based solely on it’s
> relationship to oviraptor. I was suggesting that as it has a bird-like
> egg shell, that it could have descended from a bird.
Ah. This character is unfortunately missing data for most taxa. We don't
have eggs for most theropods or for most fossil birds. I doubt that it
would constrain the tree very much if you put it in, for that reason. I
think you have to separate the characters that are simply evidence of
similarity (or if polarized the right way, of relationships) from the
characters that also suggest adaptations to flight. The egg character is
of the former type. That is, it's evidence that Oviraptor is a bird if and
only if it helps to create a tree topology in which at least two obvious
flying birds are separately basal to Oviraptor.
> Quiang G, P Currie, M Norell, and Ji Shu-An. Two feathered Dinosaurs
> from Northeastern China". Nature Vol 395. 25 June 1998.pg 753
I think that Ji is actually the surname of the first author on that one
(as well as the last author).
John Harshman
getulus@no bull.net (Cal King) wrote:
> In article
> <harshman.diespamdi...@user-2iveku7.dialup.mindspring.com>,
> harshman....@sjm.infi.net (John Harshman) wrote:
> >In article <_9of6.11373$vh.4...@bgtnsc05-news.ops.worldnet.att.net>,
> >getulus@no bull.net (Cal King) wrote:
...a post containing so many layers of misunderstanding that it would be
more trouble than I care to go to for me to unravel them. I particularly
dislike Cal's habit of forgetting what he was talking about in the
previous post, and replying to me as if there were a total absence of
context. This results in frequent, accidental changes of subject.
Anyway, I think this thread has become too convoluted to salvage.
But I will explain the concept of "missing data". Suppose you can score a
character for some number of taxa, say, feathers present in Caudipteryx
and Archaeopteryx but absent in, say, Madeuposaurus, a primitive
theropods. Unfortunately, you don't have skin samples preserved for most
other theropods; you can't tell if feathers should be listed as present or
absent for them. What do you do? You score them as "?", which means
"missing data". What happens when you analyze is that as the program
evaluates a tree for length, each ? character assumes whatever state is
most parsimonious for is to be on that tree, with the effect that the
missing data fit any tree equally well. This lets the data that are known
have their effects. In the case at hand, Caudipteryx and Archaeopteryx
would, on the basis of their feathers, be hypothesized to be more closely
related to each other than either was to Madeuposaurus. But where
Veliciraptor or Tyrannosaurus would fit in all this would have to rely on
other characters, feathers being silent.
As for feathers, there are so many taxa that would have to be scored as ?
that it would be unlikely to constrain the tree topology to any meaningful
degree.
bull.net Cal King
jumbo." The fact is that theropod skin samples are known and there simply
is no trace of feathers in those samples. Basically Harshman is arguing
that because feather has not been found on any theropod yet, therefore we
can simply ignore Caudipteryx's wing feathers. One can put any spin one
wants on this sort of practice, but the bottom line is that anyone who does
that is simply ignoring evidence. Besides, Martin pointed out that many of
the characters Gauthier used in his analysis linking dromaeosaurs and birds
are simply absent from many of the taxa he included in his analysis. That
did not stop the cladist Gauthier from using those characters. So Harshman
is in effect arguing for a double standard so that he can ignore this
particular birdlike character of Caudipteryx.
In article
<harshman.diespamdi...@user-2ivelmq.dialup.mindspring.com>,
harshman....@sjm.infi.net (John Harshman) wrote:
>....a post containing so many layers of misunderstanding that it would be
bull.net Cal King
Robinson) wrote...
>3 Oviraptors have been found laying on nest. Embryo’s attributed to
>these Oviraptor‘s have been found in two separate nests.
Does that mean Oviraptor lay two types of eggs? Is the third nest not
evidence that Oviraptor is a nest robber? If so, then the other two nests
that are associated with Oviraptor may not be Oviraptor nests either. If a
volcanic eruption covered two monitor lizards in the process of preying upon
two different crocodile nests, what would that be evidence of?
>These eggs have an ornithoid-basic shell type (often called ornithoid-
>ratite) as they are similar to ratite eggshells. These eggs are called
>Elongatoolithidae. The mammiliary layer and the outer continous layer
>are distinctly separate and are possibly indicative of a more avian
>reproductive tract. Although there are good reasons to have a
>convergent eggshell (ie special layers can be added for microbal
>protection and coloring), this shell has been used by Norell and others
>to say that bird eggs evolved from dinosaur eggs. However, thus far
>the oviraptor is the only dinosaur proven to have this shell type.
>Troodon, for example, has a prismatic egg, which is more reptilian.
Troodon is quite closely related to Oviraptor. Both are theropods. If their
eggs can differ so much, then egg type is probably of little taxonomic value.
>This same egg type has recently been found in Mid-cretaceous North
>America and has been attributed to Microvenator based solely on it’s
>relationship to oviraptor. I was suggesting that as it has a bird-like
>egg shell, that it could have descended from a bird.
>
>Thanks,
>
>Evan Robinson
>
>Quiang G, P Currie, M Norell, and Ji Shu-An. Two feathered Dinosaurs
>from Northeastern China". Nature Vol 395. 25 June 1998.pg 753
That only shows how tenuous the identification of fossil eggs can be.
Evan Robinson
defend myself, but I wanted to respond to this one part:
> >> What evidence is there that Caudipteryx did not descend from a
> >> volant bird? I have found only this, from Sereno (1999): Given the
> >> absence of basic flight related features in it’s skeleton (such as
> >> a laterally facing glenoid), there is no evidence of flight
> >> function in the ancestory of Caudipteryx”.
>
> >> My reprint is poor, but I believe that it ( Science Vol 279, 20
> >> March 1998, pg: 1917) says, regarding Rahona ostromi, a bird, :
> >> “The scapula of Rahona is probably positioned dorsally on the
> >> ribcage rather than ventrally as in theropods, resulting in a more
> >> laterally directed glenoid fossa.”
> >
John Harsman wrote:
> >I don't think Rahonavis is considered a bird by most systematists,
> >although it generally comes out very close to birds.
Cal King wrote:
> Didn't I show you a paper in which Rahonavis is said to be a member
> of the class Aves? It is, according to Feduccia (1999), most likely
> a chimera consisting of possibly both Vorona (a bird) and a theropod
> since the two halves of the fossil are disjunct.
I did not know this, is it the top half which is the bird? If so, the
laterally facing glenoid could be retained from more primitive flyers,
as could Caudipteryx's(if it’s glenoid is indeed laterally facing). I
have just read (from a Dromaeosaur paper, but originally from a paper
on the origin of avian flight): “A laterally facing glenoid is
consistant with an avian mode of movement (elevation and relevant
rotation and abduction) of the forelimb.” I would suggest that this is
either a primitive flyer feature retained by Caudipteryx, or that
Caudipteryx has re-achieved this feature through neotany, as part of
secondary flightlessness.
This laterally facing glenoid is the only evidence, other than the
placement of Caudopteryx in his tree, that Caudipteryx is not a
flightless bird, that Sereno presents in my copies. Speaking of Mr.
Sereno’s tree, this may be old news, but I was not aware of it until
now:
The Yixian Formation of China, which has produced Caudipteryx, as well
as Sinosauropteryx, Protoarchaeopteryx, Confuciusornis, and
Lianingornis has been re-dated, soundly I believe, as Middle-early
Cretaceous. Here is a quote from Nature Magazine: “The new dates
reported here in conjunction with ref. 26, indicates that the
‘feathered’ dinosaurs of Liaoning, although primitive in appearance,
are not Late Jurassic or even Earliest Cretaceous in age. Compared with
the geologic time scale of ref 25, the dates indicate a correlation
with the middle Barremian(mid-early Cretaceous), at least 20 Myr
younger than Archaeopteryx from the late Jurassic (Tithonian) Solnhofen
Limestone of Europe.”
I wonder what Mr. Sereno’s tree would look like if it were put in
chronological order?
Swisher, Carl., Yuan-qing Wang, Xiao-lin Wang, Xing Xu, Yuan Wang .
“Cretaceous age for the feathered dinosaurs of Liaonging China. Nature.
Vol. 400 .1 July,1999 pg:58
Thanks,
Evan Robinson
bull.net Cal King
<theeg...@my-deja.com> wrote:
>John Harsman wrote:
>> >I don't think Rahonavis is considered a bird by most systematists,
>> >although it generally comes out very close to birds.
>
>Cal King wrote:
>> Didn't I show you a paper in which Rahonavis is said to be a member
>> of the class Aves? It is, according to Feduccia (1999), most likely
>> a chimera consisting of possibly both Vorona (a bird) and a theropod
>> since the two halves of the fossil are disjunct.
>
>I did not know this, is it the top half which is the bird?
Probably so because the pelvis is theropodlike and there is a sickle claw
on the feet.
> If so, the
>laterally facing glenoid could be retained from more primitive flyers,
>as could Caudipteryx's(if it’s glenoid is indeed laterally facing). I
>have just read (from a Dromaeosaur paper, but originally from a paper
>on the origin of avian flight): “A laterally facing glenoid is
>consistant with an avian mode of movement (elevation and relevant
>rotation and abduction) of the forelimb.” I would suggest that this is
>either a primitive flyer feature retained by Caudipteryx, or that
>Caudipteryx has re-achieved this feature through neotany, as part of
>secondary flightlessness.
The morphometric data of Jones et al. shows that Caudipteryx has a center
of mass that resembles a flightless bird's. This is pretty good evidence,
along with the wing feathers, short tail, birdlike skull, lack of a
theropodlike caudofemoralis, reversed hallux, and posteroventral foramen
magnum, that it is indeed a bird.
>This laterally facing glenoid is the only evidence, other than the
>placement of Caudopteryx in his tree, that Caudipteryx is not a
>flightless bird, that Sereno presents in my copies. Speaking of Mr.
>Sereno’s tree, this may be old news, but I was not aware of it until
>now:
>
>The Yixian Formation of China, which has produced Caudipteryx, as well
>as Sinosauropteryx, Protoarchaeopteryx, Confuciusornis, and
>Lianingornis has been re-dated, soundly I believe, as Middle-early
>Cretaceous. Here is a quote from Nature Magazine: “The new dates
>reported here in conjunction with ref. 26, indicates that the
>‘feathered’ dinosaurs of Liaoning, although primitive in appearance,
>are not Late Jurassic or even Earliest Cretaceous in age. Compared with
>the geologic time scale of ref 25, the dates indicate a correlation
>with the middle Barremian(mid-early Cretaceous), at least 20 Myr
>younger than Archaeopteryx from the late Jurassic (Tithonian) Solnhofen
>Limestone of Europe.”
The long tail feathers of Confuciusornis and its beak are by no means
primitive. Keep in mind that true Orithurine birds such as the
Hesperornithiforms were already present by the earliest Cretaceous, and one
wonders how the "primitive" enantiornithines from China could have been
ancestral to the more "advanced" Hesperornithiform birds and their
ornithurine relatives? It appears that the Confuciusornis-ornithurine
split must have occurred much earlier than the date for this locality since
the common ancestor to both must be a toothed bird, or else the
ornithurines must have evolved teeth from a toothless ancestor, which is
of course highly unlikely.
>I wonder what Mr. Sereno’s tree would look like if it were put in
>chronological order?
>
>Swisher, Carl., Yuan-qing Wang, Xiao-lin Wang, Xing Xu, Yuan Wang .
>“Cretaceous age for the feathered dinosaurs of Liaonging China. Nature.
>Vol. 400 .1 July,1999 pg:58
>
>Thanks,
>
>Evan Robinson
I would love to see that tree in chronological order too.
Rick Toomey
Evan Robinson wrote:
> I wonder what Mr. Sereno’s tree would look like if it were put in
> chronological order?
For a discussion of the stratigraphic implications (and inconsistencies)
of the Sereno phylogeny (and others including various placements
of birds), I would recommend looking at the following:
Brochu CA and Norell MA, 2000, Temporal Congruence and the Origin
of Birds. Journal of Vertebrate Paleontology. 20: 197-200.
Rick Toomey
Illinois State Museum
too...@museum.state.il.us
White Shite
>on the feet.
In other words your criticism of the interpretation of the specimen is not
based on any resources that you have seen?
Evan Robinson
> In article <mcgg6.83$t52....@bgtnsc05-news.ops.worldnet.att.net>,
> >3 Oviraptors have been found laying on nest. Embryo’s attributed to
> >these Oviraptor‘s have been found in two separate nests.
> Does that mean Oviraptor lay two types of eggs? Is the third nest not
> evidence that Oviraptor is a nest robber? If so, then the other two
> nests that are associated with Oviraptor may not be Oviraptor nests
> either. If a volcanic eruption covered two monitor lizards in the
> process of preying upon two different crocodile nests, what would
> that be evidence of?
Sorry, I had two typos in there. Here is an original quote, from
Zelentsky et al, 2000: “Currently only two associations of embryotic
remains with elongatoolithid eggs are known. Both of these taxa are
from Asia and can be assigned to oviraptorosaurs or oviraptor-like
theropods (Norell et al., 1994; Zelenitsky, unpublished)”. So, two
nests have had elongatoolithid eggs containing embryo’s that were
assigned to oviraptors. One of these nests you were previously pointing
out was controversial. The cause of the controversy; however, was only
that a second set of embryo’s in the nest appear to belong to a
different theropod. I think though, that the only way that one could
convince anyone that these nests were misidentified, would be to
demonstrate that these embryo’s were closer to say, a protoceratops,
which seems unlikely.
On four separate nests of this type, oviraptor skeletons have been
preserved on nests of this type: “The skeleton is preserved over the
center of the nest, with it’s limbs arranged symetrically on either
side and it’s arms spread around the nest perimeter. This is one of
four known oviraptoroid skeletons preserved on nests with this type of
egg, comprising 23.5% of the 17 oviraptorid skeletons collected from
the Djadokhta Formation before 1996.”(Clark et al, 1999).
> > These eggs have an ornithoid-basic shell type (often called
> > ornithoid- ratite) as they are similar to ratite eggshells. These
> > eggs are called Elongatoolithidae. The mammiliary layer and the
> > outer continous layer are distinctly separate and are possibly
> > indicative of a more avian reproductive tract. Although there are
> > good reasons to have a convergent eggshell (ie special layers can
> > be added for microbal protection and coloring), this shell has been
> > used by Norell and others to say that bird eggs evolved from
> > dinosaur eggs. However, thus far the oviraptor is the only dinosaur
> > proven to have this shell type. Troodon, for example, has a
> > prismatic egg, which is more reptilian.
> Troodon is quite closely related to Oviraptor. Both are theropods. If
> their eggs can differ so much, then egg type is probably of little
> taxonomic value.
This is a good point Their eggs are similar in that they both are
elongate, and both are arranged in circles; however, they are very
different. Ken suggests that the Prismatoolithid (Troodon) egg is the
ancestral type, is retained by the troodon, and evolved into the later.
My pet theory is that the troodon is not so close to birds as is
assumed by it’s characters, while the oviraptor is actually closer to
birds. Paul says that while the troodon appears similar on the surface,
it is much different underneath. A troodon has always seemed like an
intelligent (well, bird-brained), land- running crocodile to me.
Oviraptor, perhaps, descended from a proto-bird.
> > This same egg type has recently been found in Mid-cretaceous North
> >America and has been attributed to Microvenator based solely on it’s
> >relationship to oviraptor. I was suggesting that as it has a bird-
> >like egg shell, that it could have descended from a bird.
> That only shows how tenuous the identification of fossil eggs can be.
Can’t argue with that.
Thanks,
Evan Robinson
Evan Robinson
> In article <3a803ae8...@news.onix.com>,
> SPAMNOTch...@onix.com wrote:
Interesting post, I'd like to work with you, but I have a few
grievances.
> On Tue, 06 Feb 2001 00:54:48 GMT, Evan Robinson
> <theeg...@my-deja.com> wrote:
>
> >... Do you really think that there is a reason to
> >have wings, that attach to your hands, unless you ancestors were
> > flyingbirds?...
> > And Cal King posted:
> >...[T]hese "hand raptors" must have known that their offsprings
> > [sic] would become birds, and that is why they evolved a set of
> > wings in anticipation of that eventuality, even though these wings
> > are not useful for either prey capture or flight. Isn't it an
> > axiom in evolutionary biology that every intermediate stage in the
> > evolution of a character must be adaptive?...
> Firstly, they aren't "wings"--they're feathered arms. That's quite a
> difference.
Secondarily flightless birds have reduced wings, especially in
comparison to their enlarged body size. The kiwi's wings have been
reduced to knubs. Thus, Caudipteryx (or oviraptor) having reduced wings
(and non-flight feathers)is not a factor.
> And there *is* an adaptive character in arm feathers that are
> obviously too short for flight.
If these are just arms, and not wings, and the feathers are short, why
are you about to suggest that they can cover large oviraptor eggs?
> I don't have a copy of the Proceedings, so please correct me if I'm
> mis-attributing, but I believe it was Tom Holtz who presented a paper
> at DINOFEST '98 that was remarkably persuasive at identifying the
> quills in question as *brood feathers*.
This sound exciting, but I cannot find anything on this. What quills?
Are these more of those "intergumentary structures", 50-70mm long?
These have never been differentiated as quills. Can you describe this
quill, it sounds interesting.
> Take a good look at the posture of the famous "brooding *Oviraptor*."
> We know she died in a sandstorm, and we can infer from the body
> posture that she was protecting her eggs when she did.
Just a point of interest, fossils such as turtles and small crocodiles
show that there were ponds and/or rivers between the sand dunes. A
modern-day varanid lizard (also present in early Mongolia) will team up
to distract the bird, while another attacks the nest. There were lots
of predators there to guard againsed.
> But protecting them with what? Most of the eggs lie *behind* her
> arms, not under them.
> But those eggs lie exactly where they'd be protected if the animal had
> short, non-flight adapted brood feathers--sketch them in with a pencil
> yourself and it's very compelling.
I’d like to try it, but for now, in Carpenter 1999 (Eggs, nests and
Baby Dinosaurs, A Look at Dinosaur Reproduction) pg: 157, Carpenter
shows a drawing of an oviraptor sitting on his/her nest. In this
picture, the oviraptor looks very silly sitting on a nest of eggs that
it can’t completely cover. The caption says: “…it is clear that many
eggs were not in contact with the body indicating that true avian
brooding did not occur.” In this depiciton, if oviraptor really wanted
to cover all of those eggs, he/she would have to have an extremely
large fan of tail feathers, as most of the eggs lie behind her.
> So here's an adaptive scenario that puts feathers on small theropods
> without any avian ancestors being necessary.
>
> First, down feathers evolve as insulation--scales don't retain heat,
> but feathers do--perfectly adaptive.
Additionally feathers come out of follicles, and are made of a
different protein than scales. A big step.
> Ever seen an avian startle reaction? If you own a parrot, you've seen
> it--the animal opens its wings to look bigger and hops upward--*not*
> launching itself into flight.
>
> If a small, feathered, non-avian theropod executed a similar reaction,
> the arms would generate some lift on the downstroke. Evolving longer
> brooding feathers would generate more lift, and...you get the picture.
The biggest threat to oviraptors were probably velociraptors and maybe
troodons. If they flapped and lifted only slightly, it seems like it
would make for an easy tackle. It is very hard for me to picture this
flapping, ground-up jump.
> Again, these ideas are not mine, they're Tom Holtz's (and, again,
> please correct me if I'm wrong on the source).
Overall, the most plausible, ground-up feather story I've ever heard
actually.
> Point is--there are adaptive reasons for the evolution of feathers
> that don't involve flight. Flight is the end result--but obviously
> not the starting point
>
> --Christopher
I don’t think that this is obvious, and I can’t quite comprehend this
brooding feather. But then, why are the oviraptors laying on their
eggs? An oviraptor can’t cover his whole nest with it’s body (ostriches
can’t either, the extra eggs are pushed to the outside as decoys for
predators), but ostriches keep the eggs warm with their bodies.
Oviraptors can't be doing this because they can't contact all of the
eggs. Sometimes the eggs (concentric circles, ends stuck in the sand)
are two layers deep, they may be unintentionally laid by two females in
the same nest, or perhaps the lower level of eggs hatches also by sand
heat, but not again, not by body contact. So they don’t seem to be
“brooded”, unless brooding for protection. An oviraptor that can cover
the whole nest with it’s wings is a interesting possiblility.
Thanks,
Evan Robinson
bull.net Cal King
<theeg...@my-deja.com> wrote:
>Sorry, I had two typos in there. Here is an original quote, from
>Zelentsky et al, 2000: “Currently only two associations of embryotic
>remains with elongatoolithid eggs are known. Both of these taxa are
>from Asia and can be assigned to oviraptorosaurs or oviraptor-like
>theropods (Norell et al., 1994; Zelenitsky, unpublished)”. So, two
>nests have had elongatoolithid eggs containing embryo’s that were
>assigned to oviraptors. One of these nests you were previously pointing
>out was controversial. The cause of the controversy; however, was only
>that a second set of embryo’s in the nest appear to belong to a
>different theropod. I think though, that the only way that one could
>convince anyone that these nests were misidentified, would be to
>demonstrate that these embryo’s were closer to say, a protoceratops,
>which seems unlikely.
I don't know how anyone else can be convinced but I am not convinced that
these eggs belong to Oviraptor. In fact, I am not even convinced that
theropods lay eggs. They may well be oviviviparous or even viviparous.
>On four separate nests of this type, oviraptor skeletons have been
>preserved on nests of this type: “The skeleton is preserved over the
>center of the nest, with it’s limbs arranged symetrically on either
>side and it’s arms spread around the nest perimeter. This is one of
>four known oviraptoroid skeletons preserved on nests with this type of
>egg, comprising 23.5% of the 17 oviraptorid skeletons collected from
>the Djadokhta Formation before 1996.”(Clark et al, 1999).
These eggs could be the favorite food for Oviraptor.
>> > These eggs have an ornithoid-basic shell type (often called
>> > ornithoid- ratite) as they are similar to ratite eggshells. These
>> > eggs are called Elongatoolithidae. The mammiliary layer and the
>> > outer continous layer are distinctly separate and are possibly
>> > indicative of a more avian reproductive tract. Although there are
>> > good reasons to have a convergent eggshell (ie special layers can
>> > be added for microbal protection and coloring), this shell has been
>> > used by Norell and others to say that bird eggs evolved from
>> > dinosaur eggs. However, thus far the oviraptor is the only dinosaur
>> > proven to have this shell type. Troodon, for example, has a
>> > prismatic egg, which is more reptilian.
>
>> Troodon is quite closely related to Oviraptor. Both are theropods. If
>> their eggs can differ so much, then egg type is probably of little
>> taxonomic value.
>
>This is a good point Their eggs are similar in that they both are
>elongate, and both are arranged in circles; however, they are very
>different. Ken suggests that the Prismatoolithid (Troodon) egg is the
>ancestral type, is retained by the troodon, and evolved into the later.
If this is the case, then the Troodon type egg would have to evolve first
into Longisquama type egg (whatever that may be) and then it would need to
evolve into bird type eggs before it would evolve into Oviraptor type eggs,
IOW a very reticulate path of evolution. That means Oviraptor is more
closely related to Longisquama than it is to Troodon. It requires massive
convergence between Troodon and Oviraptor.
>My pet theory is that the troodon is not so close to birds as is
>assumed by it’s characters, while the oviraptor is actually closer to
>birds. Paul says that while the troodon appears similar on the surface,
>it is much different underneath. A troodon has always seemed like an
>intelligent (well, bird-brained), land- running crocodile to me.
>Oviraptor, perhaps, descended from a proto-bird.
Are you suggesting that Oviraptor evolved from an animal similar to
Longisquama? Longisquama is the only animal that can be considered a
proto-bird, since all other known feathered animals are birds, not
proto-birds, notwithstanding all the fanciful reconstructions that put
feathers on all sorts of theropods, including Scipionyx.