C*l K*ng come back, all is forgiven; and paleognaths too
John Harshman
usenet loons. And not very interesting ones, either. At least Cal was
amusing at times, and discussions with him bore some resemblance to real
discussions of paleontology. I suppose this will pass. It's happened
before, and the sooner people stop responding, or at least remove
irrelevant newsgroups before responding, the sooner they will leave.
To add some on-topic content, does anyone have a reference to paleognath
fossils that I don't? Especially flying paleognaths. Aside from a couple
of papers by Peter Houde on lithornithiforms, I don't see much.
Ken Shaw
John Harshman wrote:
If he comes back I'm going to remind you about this post.
BTW thanks for recommending _Dinosaurs of the Air_ a while back, I just
finished it and have some serious thinking to do.
I'm still not sure whether the maniraptorans are secondarily flightless
but I think the case is pretty strong. Though I'm still struggling with
where to put therizinosaurs. Especially if there is an early jurassic
specimen.
Ken
John Harshman
Ken Shaw wrote:
>
>
> John Harshman wrote:
>
>> A lament: sci.bio.paleontology seems to have been taken over entirely
>> by usenet loons. And not very interesting ones, either. At least Cal
>> was amusing at times, and discussions with him bore some resemblance
>> to real discussions of paleontology. I suppose this will pass. It's
>> happened before, and the sooner people stop responding, or at least
>> remove irrelevant newsgroups before responding, the sooner they will
>> leave.
>>
>> To add some on-topic content, does anyone have a reference to
>> paleognath fossils that I don't? Especially flying paleognaths. Aside
>> from a couple of papers by Peter Houde on lithornithiforms, I don't
>> see much.
>
> If he comes back I'm going to remind you about this post.
You will note I used asterisks, just in case.
> BTW thanks for recommending _Dinosaurs of the Air_ a while back, I just
> finished it and have some serious thinking to do.
>
> I'm still not sure whether the maniraptorans are secondarily flightless
> but I think the case is pretty strong.
Not sure if all of them are, but I think Microraptor gui is, all by
itself, a fairly good argument that at least dromaeosaurs had at least
gliding ancestors.
> Though I'm still struggling with
> where to put therizinosaurs. Especially if there is an early jurassic
> specimen.
There are certainly plenty of options to choose from. I don't think any
two cladograms have agreed. Too many highly transformed characters. They
are also apparently not the only herbivorous theropods, if you count
Caudipteryx's gizzard stones as evidence.
John Brock
John Harshman <jharshman....@pacbell.net> wrote:
>A lament: sci.bio.paleontology seems to have been taken over entirely by
>usenet loons. And not very interesting ones, either. At least Cal was
>amusing at times, and discussions with him bore some resemblance to real
>discussions of paleontology. I suppose this will pass. It's happened
>before, and the sooner people stop responding, or at least remove
>irrelevant newsgroups before responding, the sooner they will leave.
I think there is a useful distinction to be made between a "crank"
and a "crackpot". Cal was a crank. He knew a lot about his subject,
and his arguments at least approximated coherence. The new guys
are crackpots; they don't come anywhere close to making sense.
Personally I find crackpots rather easier to deal with. I simply
ignore any thread in which their names appear. Cranks are more
difficult, because you feel you *ought* to be able to have a sensible
discussion with them, any yet, somehow, you can't.
--
John Brock
jbr...@panix.com
evan robinson
> wrote to John Harshman:
>
> BTW thanks for recommending _Dinosaurs of the Air_ a while back, I just
> finished it and have some serious thinking to do.
"That all basal dino-avian fliers show adaptations for arboreality
demolish both the belief that dinosaurs could not be arboreal, and
that dinosaurs learned to fly from the ground up."- Gregory Paul
(Newsgroup post).
> I'm still not sure whether the maniraptorans are secondarily flightless
> but I think the case is pretty strong.
Rear wings on the basal dromaeosaur Microraptor.
> Though I'm still struggling with where to put therizinosaurs.
Why not in secondarily flightless?
> Especially if there is an early jurassic specimen.
What is the early Jurrasic Specimen, is it that partial jawbone? I
would expect to see early Jurrasic Therizinosaurs.
Beipiaosaurus, a small basal therizinosaur, has elongated (7cm)
integumentary fibers on its arms. Neimongosaurus has an elongated
neck, shortened tail, highly pneumatized vertebra and derived shoulder
girdle. The radius has a prominent biceps tuberosity, close to the
proximal end of the radius (Zhang et al 2001 ). A "prominate" radial
biceps tuberosity is present only in the therizinosaur Neimongosaurus,
dromaeosaur Microraptor (Xu et al 2002), and avians (Gardener 2003).
Other features of the shoulder also sound rather advanced: "there is
a large coracoid tubercle and a coracoid forming a tight angle from
the scapula, the coracoid very large and high" (Jaimme Headden). The
coracoid tubercle is well developed and projects laterally as a
pyramidal eminence."(Zhang et al).
Given this advanced shoulder, and not being a fan of WAIR, I can only
conclude that the ancestor of Neimongosaurus was volant. Similarly, I
see no other reason for the elongated arm integument on Beipiasaurus.
Out of the loop here for a while, so I hope my info is not outdated.
Thanks,
Evan Robinson
Ken Shaw
evan robinson wrote:
>>Ken Shaw <non...@your.biz> wrote in message news:<NPjgc.43871>
>>wrote to John Harshman:
>>
>>BTW thanks for recommending _Dinosaurs of the Air_ a while back, I just
>>finished it and have some serious thinking to do.
>
>
> "That all basal dino-avian fliers show adaptations for arboreality
> demolish both the belief that dinosaurs could not be arboreal, and
> that dinosaurs learned to fly from the ground up."- Gregory Paul
> (Newsgroup post).
>
>
>>I'm still not sure whether the maniraptorans are secondarily flightless
>>but I think the case is pretty strong.
>
>
> Rear wings on the basal dromaeosaur Microraptor.
>
>
>>Though I'm still struggling with where to put therizinosaurs.
>
>
> Why not in secondarily flightless?
>
>
>>Especially if there is an early jurassic specimen.
>
>
> What is the early Jurrasic Specimen, is it that partial jawbone? I
> would expect to see early Jurrasic Therizinosaurs.
Here is the problem. For Therizinosaurs to be secondarily flightless and
the partial jawbone is from one that has to push back the development of
feathers and flight back into the early jurassic if not into the triassic.
This would make quite a mess of every existing cladogram of the
theropods. To start with it would require either removing the aves from
inside Coelurosauria or pushing the clade back to into the early
jurassic or the triassic.
Until more solid evidence for the origin of aves that early appears I
will withhold judgment.
>
> Beipiaosaurus, a small basal therizinosaur, has elongated (7cm)
> integumentary fibers on its arms. Neimongosaurus has an elongated
> neck, shortened tail, highly pneumatized vertebra and derived shoulder
> girdle. The radius has a prominent biceps tuberosity, close to the
> proximal end of the radius (Zhang et al 2001 ). A "prominate" radial
> biceps tuberosity is present only in the therizinosaur Neimongosaurus,
> dromaeosaur Microraptor (Xu et al 2002), and avians (Gardener 2003).
> Other features of the shoulder also sound rather advanced: "there is
> a large coracoid tubercle and a coracoid forming a tight angle from
> the scapula, the coracoid very large and high" (Jaimme Headden). The
> coracoid tubercle is well developed and projects laterally as a
> pyramidal eminence."(Zhang et al).
>
> Given this advanced shoulder, and not being a fan of WAIR, I can only
> conclude that the ancestor of Neimongosaurus was volant. Similarly, I
> see no other reason for the elongated arm integument on Beipiasaurus.
>
I am fairly confident that Therizinosaurs are derived coelurosaurs but
there are several characters that keep me from being convinced. The
extra toe is a significant one.
> Out of the loop here for a while, so I hope my info is not outdated.
>
> Thanks,
>
> Evan Robinson
Ken
John Harshman
Ken Shaw wrote:
Not true. Have you seen Paul's cladogram? It doesn't do that much
violence to the standard views. The point of all this is exactly that
there is no connection between the origin of Aves (a topologically
defined clade) and the origin(s) of flight in theropods. Aves is a
coelurosaur regardless of just when its ancestors started flying, and
how many of its relatives are secondarily flightless. What is required
is that there be a lot of undiscovered small, flying theropods, possibly
extending into the early Jurassic or even further. What we need is an
early Jurassic Liaoning.
> Until more solid evidence for the origin of aves that early appears I
> will withhold judgment.
I think the origin of Aves is fairly solid. The origin of flight is
quite another question.
>> Beipiaosaurus, a small basal therizinosaur, has elongated (7cm)
>> integumentary fibers on its arms. Neimongosaurus has an elongated
>> neck, shortened tail, highly pneumatized vertebra and derived shoulder
>> girdle. The radius has a prominent biceps tuberosity, close to the
>> proximal end of the radius (Zhang et al 2001 ). A "prominate" radial
>> biceps tuberosity is present only in the therizinosaur Neimongosaurus,
>> dromaeosaur Microraptor (Xu et al 2002), and avians (Gardener 2003).
>> Other features of the shoulder also sound rather advanced: "there is
>> a large coracoid tubercle and a coracoid forming a tight angle from
>> the scapula, the coracoid very large and high" (Jaimme Headden). The
>> coracoid tubercle is well developed and projects laterally as a
>> pyramidal eminence."(Zhang et al).
>>
>> Given this advanced shoulder, and not being a fan of WAIR, I can only
>> conclude that the ancestor of Neimongosaurus was volant. Similarly, I
>> see no other reason for the elongated arm integument on Beipiasaurus.
WAIR?
Ken Shaw
John Harshman wrote:
Paul's cladogram seems to easy for me. There seems to be a lot of
transitions from flying to secondarily flightless in this cladogram.
Evidence from existing secondarily flightless birds is that they mostly
appear in conditions of isolation. While therizinosaurs seem to be
something likely to have evolved in isolation the maniraptorans seem
adapted to a very dynamic competitive environment.
But I still have some researched thinking to do.
>> Until more solid evidence for the origin of aves that early appears I
>> will withhold judgment.
>
>
>
> I think the origin of Aves is fairly solid. The origin of flight is
> quite another question.
Never ever post until I finish my first cup of coffee. I meant origin of
flight and feathers.
Ken
John Harshman
Ken Shaw wrote:
>
>
> John Harshman wrote:
>
>>
>>
>> Ken Shaw wrote:
[snip]
Yet another caveat: don't confuse the two. The bet is that feathers
precede flight by quite a bit.
Mickey Mortimer
knowledge. He shall never return.
Contrary to Harshman, almost all recent phylogenetic analyses agree
segnosaurs are the sister clade of oviraptorosaurs. Kirkland's new
basal form is yet more evidence for Enigmosauria.
And yes, the Early Jurassic possible segnosaur is Eshanosaurus, known
from a dentary and splenial. Segnosaur-like, and sauropodomorph-like.
Could be either.
Ken Shaw- the enlarged metatarsal I of segnosaurs shouldn't be an
issue because the most basal segnosaur with a known foot-
Beipiaosaurus, is typically theropod in this regard.
John Harshman- WAIR is described in-
Dial, K.D. 2003. Wing-Assisted Incline Running and the evolution of
flight.
Science 299: 402-404.
Mickey Mortimer
johnscanlon
For a current illustration (very many of them, actually), Cal performs
almost live and almost continuously on a couple of herpetology
discussion groups, Fieldherpers.com (genetics and systemaics) and
Kingsnake.com (taxonomy). Any of you who saw his last-ditch defense of
the losing anti-dinosaurian position can drop in for a dose of deja vu
as he continues to battle windmills and wander in magic caves...
evan robinson
> news:<ebbaf990.0404...@posting.google.com>...
> Bah! Cal King was utterly destroyed by my weapons of logic and
> knowledge. He shall never return.
You do share his level of high confidence.
> Contrary to Harshman, almost all recent phylogenetic analyses agree
> segnosaurs are the sister clade of oviraptorosaurs. Kirkland's new
> basal form is yet more evidence for Enigmosauria.
Can you tell us about the new Enigmosaur?
> And yes, the Early Jurassic possible segnosaur is Eshanosaurus, known
> from a dentary and splenial. Segnosaur-like, and sauropodomorph-like.
> Could be either.
Isn't hard to say exactly what the rest of this beast looked like even
if it was a segnosaur? Perhaps in the earliest Jurassic, a
therizinosaur would not exactly be a "therizinosaur.", rather, you
know, some sort of hodge-podge. How about something like an early
Scanscoriopteryx, in this case with a specialized dentary.
Scanscoriopteryx is envisioned by S. Czerkas to be a "pre-theropod",
"proto-maniraptor", "basal arboreal saurischian". (I know, I'm sure
that exact description is not supported).
Jurassic Scansoriopteryx is heavily proto-feathered, perching clawed,
long metacarpaled, and has a greater arm length than any known
theropod (Czerkas 2002) . Given those characters, I'll bet some day we
will find a volant Scanscoriopteyx.
> Ken Shaw- the enlarged metatarsal I of segnosaurs shouldn't be an
> issue because the most basal segnosaur with a known foot-
> Beipiaosaurus, is typically theropod in this regard.
So, a basal segnosaur resembles a 2F-looking theropod.
> John Harshman- WAIR is described in-
> Dial, K.D. 2003. Wing-Assisted Incline Running and the evolution of
> flight.
> Science 299: 402-404.
>
> Mickey Mortimer
Dial discovered that extant partridges and chicken chicks flap their
wings to add traction while escaping up inclined trees. While WAIR
certainly exists in extant and extinct birds, it is certainly not
proven to be a factor in the early evolution of feathers or wings.
For example, consider this excerpt from Dial's paper:
"To investigate the contribution of the wings to inclined running
through ontogeny, I compared the performance of unmodified control
partridges to that of birds whose flight feathers *(remiges) were
trimmed to half of the normal surface area and that of birds whose
remiges were completely removed. Measured performance was similar
among groups during the initial post hatching period where the
surface area of control and modified wings were comparible. After the
seventh day post hatching, however, reduction in the remiges
significantly decreased the maximum slope that the modified birds
could ascend."
What this is saying to me is that as soon as the bird became larger
than a seven day old chicken, short remiges could not produce WAIR!
Thus in its incipient stages, short hairs on what were probably not
yet wings would not produce the desired effect. This brings your
proto-bird back to the old ground-up scenario of attempting to evolve
wings using counterproductive, energy wasting, drag-creating
weak-flapping. Poor Caudipteryx would be back to catching flies. Even
so, we would be back to needing tiny dinosaurs in trees, and these
probably jumped out.
Thanks,
Evan Robinson
John Harshman
Mickey Mortimer wrote:
> Bah! Cal King was utterly destroyed by my weapons of logic and
> knowledge. He shall never return.
>
> Contrary to Harshman, almost all recent phylogenetic analyses agree
> segnosaurs are the sister clade of oviraptorosaurs. Kirkland's new
> basal form is yet more evidence for Enigmosauria.
What's recent? I seem to recall that at the Ostrom meeting, all three
people who presented cladograms (Sereno, Holtz, Curry, Norell et al.)
had a different position for therezinosaurs/segnosaurs. Looking at the
symposium volume, which may bear some resemblance to the symposium
talks, I see that Sereno has them as sister to ornithomimids, Holtz and
Norell et al. as sister to oviraptorosaurs, and Curry didn't make it in.
Dawid Mazurek
Someone mentioned about teoreticall possibility of finding feathers down
the early jurassic. This have already happened, even before first featered
dinosaurs finds from Liaoning, Polish paleontologist Gerard Gierlinski
identified feathers imprints in a XIX collection of tracks from 200 Ma of
Massachussetts. the track belong to a ceratosaur, most propably
Dilofosaurus. This featehres are of type 2 or 3b of Prum & Brush' model, so
feathers must have arose in traissic. And this find is the first real proof
of dinosaurs having feathers.
In Poland have been find birds tracks that are some 60 Ma older than
Archeopteryx.
This two finds (oldest bird track from Poland and oldest fossilisated
feathers; both discovered by Gierlinski), have been found before first finds
from Lianing, but they seem forgetten.
As for first feathers, as far as I know evo-devo shows that they did not
arose from scales but arose de novo from skin.
Sorry for my really horrible English. Hope my message can be understood.
Cheers, David.
Dawid Mazurek
http://www.app.pan.pl/acta47/app47-097.pdf
John Harshman
Dawid Mazurek wrote:
> Hello. I'd like to tell what I think about it.
> Someone mentioned about teoreticall possibility of finding feathers down
> the early jurassic. This have already happened, even before first featered
> dinosaurs finds from Liaoning, Polish paleontologist Gerard Gierlinski
> identified feathers imprints in a XIX collection of tracks from 200 Ma of
> Massachussetts. the track belong to a ceratosaur, most propably
> Dilofosaurus. This featehres are of type 2 or 3b of Prum & Brush' model, so
> feathers must have arose in traissic. And this find is the first real proof
> of dinosaurs having feathers.
> In Poland have been find birds tracks that are some 60 Ma older than
> Archeopteryx.
> This two finds (oldest bird track from Poland and oldest fossilisated
> feathers; both discovered by Gierlinski), have been found before first finds
> from Lianing, but they seem forgetten.
Do you have complete citations for either of these? And how do you
distinguish a bird track from any other theropod track? This has been a
big problem in paleo.
Dawid Mazurek
in Polish popular-science journals and books. I can reccomend You to contact
Gerard Gierlinski for yourself and ask him. I'm just a paleontology
enthusiast and am not an expert on this subject.
Googling I found this:
http://www.cmnh.org/dinoarch/2001Jan/msg00354.html
Unfortunatelly those guys say the imprints on Ac 1/7 were not feathers. I'm
not an expert so i don't know. I wrote my message only because i heard about
ht finds.
Found also adress of Gierlinski:
http://members.shaw.ca/rtmccrea/gerard_gierlinski.htm
Didn't found anything about bird track, but I did only one search (for
"Gerard Gierlinski"), so try searching for yourself and mayby You will find
somthing. I've got a lot of popular Polish articles were both those findings
are mentioned. I can try to scan and send You a photo of this bird track, if
you're interested.
Cheers, David.
John Harshman
Dawid Mazurek wrote:
> Unoftunatelly I have no references. I read sever times about this findings
> in Polish popular-science journals and books. I can reccomend You to contact
> Gerard Gierlinski for yourself and ask him. I'm just a paleontology
> enthusiast and am not an expert on this subject.
>
> Googling I found this:
> http://www.cmnh.org/dinoarch/2001Jan/msg00354.html
> Unfortunatelly those guys say the imprints on Ac 1/7 were not feathers. I'm
> not an expert so i don't know. I wrote my message only because i heard about
> ht finds.
And I found this: Gerard Gierlinski: Feather-like Impressions in a
Theropod Resting Trace from the Lower Jurassic of Massachusetts, 179 --
184, in
Michael Morales (ed.): The Continental Jurassic, Museum of Northern
Arizona Bulletin 60, 1996
> Found also adress of Gierlinski:
> http://members.shaw.ca/rtmccrea/gerard_gierlinski.htm
>
> Didn't found anything about bird track, but I did only one search (for
> "Gerard Gierlinski"), so try searching for yourself and mayby You will find
> somthing. I've got a lot of popular Polish articles were both those findings
> are mentioned. I can try to scan and send You a photo of this bird track, if
> you're interested.
No, thanks. I want to see the publication.
Mickey Mortimer
> As for 2-F dinosaurs, an interesting article can be found here:
> http://www.app.pan.pl/acta47/app47-097.pdf
That analysis is highly flawed. It didn't include the most birdlike
deinonychosaurs (Bambiraptor, Sinornithosaurus, Microraptor), nor any
post-Archaeopteryx birds besides the strangely oviraptorid-like
confuciusornithids (Rahonavis, Yandangornis, Jibeinia,
enantiornithines, etc.).
Of their four synapomorphies placing oviraptorosaurs and birds
together, the basal oviraptorosaur Incisivosaurus lacks two (maxillary
and dentary teeth absent), while most non-confuciusornithid basal
birds lack all of them (maxillary and dentary teeth absent; lateral
cotyle in quadrate; tightly sutured dentary symphysis).
Mickey Mortimer
Mickey Mortimer
> What's recent? I seem to recall that at the Ostrom meeting, all three
> people who presented cladograms (Sereno, Holtz, Curry, Norell et al.)
> had a different position for therezinosaurs/segnosaurs. Looking at the
> symposium volume, which may bear some resemblance to the symposium
> talks, I see that Sereno has them as sister to ornithomimids, Holtz and
> Norell et al. as sister to oviraptorosaurs, and Curry didn't make it in.
Sereno's the only one who supported arctometatarsalian segnosaurs.
However, in Zhang et al. (2001) and Xu et al. (2002), he seems more
sympathetic to a segnosaur-oviraptorosaur clade. Note Sereno's
"analyses" never test alternate relationships anyway, so aren't
representative of what current data indicates at any given time.
Holtz has found a segnosaur-oviraptorosaur clade since 1996, including
unpublished stuff from SVP 2003.
The Theropod Working Group (Norell, Clark, Makovicky, etc.) has found
a segnosaur-oviraptorosaur clade in every version of their analysis,
since 2001 (even in their early Makovicky and Sues, 1998 paper).
Rauhut (2003) found a segnosaur-oviraptorosaur clade, as did Longrich
(2001), Xu et al. (1999), and Sues (1997). The only analyses besides
Sereno's (1999) that I can think of that didn't find it were Russell
and Dong (1993) and Maryanska et al. (2002). Both have unusual
topologies caused by several problems.
I haven't seen segnosaurs in any of Currie's few analyses (Currie and
Carpenter, 2000; Azuma and Currie, 2000; Currie and Varricchio, 2004).
Where does he place them?
Dawid Mazurek wrote-
> Someone mentioned about teoreticall possibility of finding feathers down
> the early jurassic. This have already happened, even before first featered
> dinosaurs finds from Liaoning, Polish paleontologist Gerard Gierlinski
> identified feathers imprints in a XIX collection of tracks from 200 Ma of
> Massachussetts. the track belong to a ceratosaur, most propably
> Dilofosaurus. This featehres are of type 2 or 3b of Prum & Brush' model, so
> feathers must have arose in traissic. And this find is the first real proof
> of dinosaurs having feathers.
> In Poland have been find birds tracks that are some 60 Ma older than
> Archeopteryx.
> This two finds (oldest bird track from Poland and oldest fossilisated
> feathers; both discovered by Gierlinski), have been found before first finds
> from Lianing, but they seem forgetten.
Because they're invalid. The Early Jurassic sitting grallatorid
imprint turned out to have an imprint of sliding vegetation, not
feathers. Identical imprints are found throughout the formation, and
associated in non-sensical ways with other footprints as well. See
http://www.cmnh.org/dinoarch/2001Jan/msg00345.html
The Triassic footprints described by Gierlinski (Trisauropodiscus) are
from ornithischians (see
http://www.ldeo.columbia.edu/~emmar/research/JVP2191.html). There are
some extremely birdlike Late Triassic prints from elsewhere (Melchor
et al., 2002), but even the authors of this paper are careful to state
such prints do not necessarily indicate birds.
References-
Gierlinski, 1996. Feather-Like Impressions in a Theropod Resting Trace
from the lower Jurassic of Massachusetts. in Morales M. (ed), The
Continental Jurassic. Museum of Northern Arizona Bulletin 60: 179-184.
Gierlin´ ski, G. Avialian theropod tracks from the Early Jurassic
strata of Poland. Zubia 14, 79–87 (1996).
Melchor, de Valais and Genise, 2002. Bird-like fossil footprints from
the Late Triassic. Nature 417, 936 - 938.
Mickey Mortimer
John Harshman
Mickey Mortimer wrote:
> John Harshman wrote-
[snip]
> Note Sereno's
> "analyses" never test alternate relationships anyway, so aren't
> representative of what current data indicates at any given time.
Why do you say that? He analyzes complete matrices by parsimony, same as
everyone else.
> I haven't seen segnosaurs in any of Currie's few analyses (Currie and
> Carpenter, 2000; Azuma and Currie, 2000; Currie and Varricchio, 2004).
> Where does he place them?
I don't remember. I had notes somewhere, but can't place them now. And I
don't know if it's published. But they were in the tree he presented at
the Ostrom meeting.
[snip]
Mickey Mortimer
> > Note Sereno's
> > "analyses" never test alternate relationships anyway, so aren't
> > representative of what current data indicates at any given time.
>
> Why do you say that? He analyzes complete matrices by parsimony, same as
> everyone else.
Technically true, but he doesn't include many characters whose
distribution doesn't agree with his phylogeny. So it's no surprise
the most parsimonious trees are those whose supporting characters he
includes. You can tell by looking at his consistancy indices (CI's).
This is the ratio of characters used to how often the character had to
change state in the cladogram. The highest it can be is 1.0 (every
character only had to change state once). If it's 0.5, on average,
every character had to change states twice (which is equivalent to it
reversing once, or evolving convergently in two groups). The analyses
in his 1999 paper had CI's ranging from .89-.97. Holtz's 2000
analysis has a CI of .44 for comparison. The Theropod Working Group's
latest analysis (Hwang et al., 2004) has a CI of .43. Sereno's
"analyses" show what he wants them to, Holtz's and the TWG's show what
comparatively unbiased data suggests.
> > I haven't seen segnosaurs in any of Currie's few analyses (Currie and
> > Carpenter, 2000; Azuma and Currie, 2000; Currie and Varricchio, 2004).
> > Where does he place them?
>
> I don't remember. I had notes somewhere, but can't place them now. And I
> don't know if it's published. But they were in the tree he presented at
> the Ostrom meeting.
Doubt it's been published, as I haven't heard of it.
Mickey Mortimer
John Harshman
Mickey Mortimer wrote:
>>John Harshman wrote-
>>
>
>>>Note Sereno's
>>>"analyses" never test alternate relationships anyway, so aren't
>>>representative of what current data indicates at any given time.
>>>
>>Why do you say that? He analyzes complete matrices by parsimony, same as
>>everyone else.
>>
>
> Technically true, but he doesn't include many characters whose
> distribution doesn't agree with his phylogeny. So it's no surprise
> the most parsimonious trees are those whose supporting characters he
> includes. You can tell by looking at his consistancy indices (CI's).
> This is the ratio of characters used to how often the character had to
> change state in the cladogram. The highest it can be is 1.0 (every
> character only had to change state once). If it's 0.5, on average,
> every character had to change states twice (which is equivalent to it
> reversing once, or evolving convergently in two groups). The analyses
> in his 1999 paper had CI's ranging from .89-.97. Holtz's 2000
> analysis has a CI of .44 for comparison. The Theropod Working Group's
> latest analysis (Hwang et al., 2004) has a CI of .43. Sereno's
> "analyses" show what he wants them to, Holtz's and the TWG's show what
> comparatively unbiased data suggests.
Congratulations. You have found a use for CI. (Dave Swofford contends
that it's absolutely useless.) This is pretty convincing. I've seen
suspiciously high CIs in other data before too (not theropods, or at
least not extinct ones) and have come to similar conclusions. I just
hadn't looked at Sereno's.
>>>I haven't seen segnosaurs in any of Currie's few analyses (Currie and
>>>Carpenter, 2000; Azuma and Currie, 2000; Currie and Varricchio, 2004).
>>> Where does he place them?
>>>
>>I don't remember. I had notes somewhere, but can't place them now. And I
>>don't know if it's published. But they were in the tree he presented at
>>the Ostrom meeting.
>>
>
> Doubt it's been published, as I haven't heard of it.
Or it could be one of those you cite above, and I am misremembering that
it included segnosaurs. Is that name becoming the standard now, and
therizinosaurs disappearing, by the way?
Mickey Mortimer
> Congratulations. You have found a use for CI. (Dave Swofford contends
> that it's absolutely useless.) This is pretty convincing. I've seen
> suspiciously high CIs in other data before too (not theropods, or at
> least not extinct ones) and have come to similar conclusions. I just
> hadn't looked at Sereno's.
Yes, I've noticed it in lots of analyses too. I generally don't trust
analyses with high CI's, though I'm not sure what a good cut-off point
should be. Maybe one could check molecular analyses to see their
CI's, where having biased character choice is not a problem.
> > Doubt it's been published, as I haven't heard of it.
>
> Or it could be one of those you cite above, and I am misremembering that
> it included segnosaurs. Is that name becoming the standard now, and
> therizinosaurs disappearing, by the way?
Perhaps.
I'm stubborn in my continual use of Segnosauria over
Therizinosauroidea. I dislike the fact Russell and Dong (1993) just
decided to come up with a new suprafamilial term for the group, when
one already existed. And then everybody starts using the new one. My
own theory is that they did it to make their (at the time
controversial) placement of segnosaurs within Theropoda more
appealling. After all, Therizinosaurus was placed in Theropoda more
often than Segnosaurus was. Unfortunately, Therizinosauroidea has
phylogenetic definitions associated with it, and will probably be
preferred by Phylocode due to that, and the fact it's been used more
this past decade. Grumble...
Mickey Mortimer
John Harshman
Mickey Mortimer wrote:
> John Harshman wrote-
>
>
>>Congratulations. You have found a use for CI. (Dave Swofford contends
>>that it's absolutely useless.) This is pretty convincing. I've seen
>>suspiciously high CIs in other data before too (not theropods, or at
>>least not extinct ones) and have come to similar conclusions. I just
>>hadn't looked at Sereno's.
>>
>
> Yes, I've noticed it in lots of analyses too. I generally don't trust
> analyses with high CI's, though I'm not sure what a good cut-off point
> should be. Maybe one could check molecular analyses to see their
> CI's, where having biased character choice is not a problem.
They're all over the place. It just depends on the data and the tree.
I've had some in the 90's and some in the 40's. Mike Sanderson had a
paper some years back that showed correlation between CI and number of
taxa, as well as no significant differences between molecular and
morphological distributions. Perhaps it's time to update the study,
given the recent explosion of nuclear data.
>>>Doubt it's been published, as I haven't heard of it.
>>>
>>Or it could be one of those you cite above, and I am misremembering that
>>it included segnosaurs. Is that name becoming the standard now, and
>>therizinosaurs disappearing, by the way?
>>
>
> Perhaps.
> I'm stubborn in my continual use of Segnosauria over
> Therizinosauroidea. I dislike the fact Russell and Dong (1993) just
> decided to come up with a new suprafamilial term for the group, when
> one already existed. And then everybody starts using the new one. My
> own theory is that they did it to make their (at the time
> controversial) placement of segnosaurs within Theropoda more
> appealling. After all, Therizinosaurus was placed in Theropoda more
> often than Segnosaurus was. Unfortunately, Therizinosauroidea has
> phylogenetic definitions associated with it, and will probably be
> preferred by Phylocode due to that, and the fact it's been used more
> this past decade. Grumble...
Plus it just sounds better. Therizinosaur has zip. Segnosaur just sits
there.