Fabulous Triassic Menagerie

[Peter Nyikos]

I've long been familiar with some strange critters of the Triassic, but I was
really amazed at the variety that was displayed for us by Gary Meany, in Quora, of all places:
https://www.quora.com/What-is-the-most-interesting-period-in-the-ancient-history-of-Earth-Is-it-the-Triassic-the-Jurassic-the-Cambrian-the-Devonian-or-other/answer/Gary-Meaney?ch=10&oid=274867839&share=f557083a&srid=pChjI&target_type=answer

He starts out:
"It’s like choosing a favourite child, honestly, but I think I’ll go with the Triassic for today. This period started about 251 million years ago, immediately preceded by the infamous End-Permian Extinction - the most devastating extinction event in Earth’s history.

"The cause of this mass extinction, also known as the Great Dying, is debated, but we do know it was immensely lethal. It’s thought that nearly 60% of all biological families were wiped out, including 70% of the world’s land vertebrate species. What this means is that, entering the Triassic, evolution practically had a clean slate to experiment with."


Then the fun begins: one unusual animal after another, each one with a well-executed color picture. Some I was familiar with:

*Tanystropheus,* with a giraffe-like neck with a few long bones, attached to a simple lizard-like body;

*Longisquama,* sporting a double row of long feather-like objects along its back;

*Sharovipteryx,* with legs much longer than its arms, but with a glidiing membrane
attached to its legs and the proximal part of its tail; and no gliding membrane elsewhere;

*Desmatosuchus*, "a herbivore built like a tank. It bore a striking resemblance to the ankylosaurs, dinosaurs which only evolved long after this reptile went extinct."


But the list stretches on and on, with many another weird creature that I've never heard of before. A few of them:

The archosaur *Erythrosuchus*, "which had a gigantic, bone-crushing head; proportionally, the largest of any known land vertebrate, extinct or otherwise."

"*Scleromochlus*, a cross between a lizard and a kangaroo. Its back legs were long and springy, enabling it to move around by hopping."

Marine reptiles included:
"*Atopodentatus, a hilariously odd creature which had a flat, hammer-shaped head. It used this to sieve through the sediment, like an underwater vacuum cleaner."

" The as of yet unnamed Lilstock Ichthyosaur. Discovered in 2018, this species may have been the largest reptile of all time, measuring a staggering 26 metres in length. Some argue it could even be comparable in size to the modern blue whale, but the evidence of this is shaky."


As the saying goes, though, a picture is worth a thousand words, and I think it best to stop here
and to let readers have the pleasure of going through the seemingly never-ending pictures for themselves.


Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos

[John Harshman]

Fascinating site. I do have to wonder how much in the reconstructions is
based on actual material. I would also like to see more phylogenetic
context. I think some of the beaked reptiles are rhynchosaurs, but I'm
not sure. And there's as least one incorrect fact: Gerrothorax was a
temnospondyl, not a reptile. Still, interesting.

[John Harshman]

On 9/22/23 6:43 PM, Peter Nyikos wrote:

Check out Gigatitan, shown next to Longisquama.

[erik simpson]

Amazing bestiary. I'll be tracking down references for a while. I've known of some of them, but there are
several new to me.

[Sight Reader]

On Friday, September 22, 2023 at 8:39:48 PM UTC-6, John Harshman wrote:
<snip original post>

> Fascinating site. I do have to wonder how much in the reconstructions is
> based on actual material. I would also like to see more phylogenetic
> context. I think some of the beaked reptiles are rhynchosaurs, but I'm
> not sure. And there's as least one incorrect fact: Gerrothorax was a
> temnospondyl, not a reptile. Still, interesting.

Hmm… he must have repaired that Gerrothorax reference as it now shows up right after the temnospondyls Trematosaurus and Mastodonsaurus. I’m thinking he deliberately avoided phylogenetic terms to keep from scaring away laymen testing out their interest in the topic.

He does have Hyperodapedon in there who would be your “classic” beaked rhynchosaur. Beyond that, I would guess that too many weird new guys - some of whom could very well have beaks - keep popping up in that “protorosaur” tree to say who’s related to what. Didn’t that whole “allokotosaur” subtree, for instance, only come into focus a decade or so ago?

[erik simpson]

I've found that the reason I recalled some of these beasts is that they almost all appear in Prothero's "Vertebrate Evolution",
which I've mostly read. (Having a capricious memory, I can't begin to claim to have all, or even most of the information
presented in that text in hand.). Prothero's text isn't to be compared to Romer's magisterial (but sadly now out of date)
compendium, but it's more approachable, particular for amateurs.

[Kerr-Mudd, John]

On Fri, 22 Sep 2023 18:43:11 -0700 (PDT)
Peter Nyikos <peter2...@gmail.com> wrote:

> I've long been familiar with some strange critters of the Triassic, but I was
> really amazed at the variety that was displayed for us by Gary Meany, in Quora, of all places:
> https://www.quora.com/What-is-the-most-interesting-period-in-the-ancient-history-of-Earth-Is-it-the-Triassic-the-Jurassic-the-Cambrian-the-Devonian-or-other/answer/Gary-Meaney?ch=10&oid=274867839&share=f557083a&srid=pChjI&target_type=answer
>
> He starts out:
> "It’s like choosing a favourite child, honestly, but I think I’ll go with the Triassic for today. This period started about 251 million years ago, immediately preceded by the infamous End-Permian Extinction - the most devastating extinction event in Earth’s history.
>
> "The cause of this mass extinction, also known as the Great Dying, is debated, but we do know it was immensely lethal. It’s thought that nearly 60% of all biological families were wiped out, including 70% of the world’s land vertebrate species. What this means is that, entering the Triassic, evolution practically had a clean slate to experiment with."
>
>
> Then the fun begins: one unusual animal after another, each one with a well-executed color picture.

Clearly there's far too much variety there for some simplistic thing
called 'Evolution' to have created so many different creatures;
what is needed is a Designer. </tongue in cheek>

--
Bah, and indeed Humbug.

[Sight Reader]

Good Lord! Are you saying that this Prothero book is actually able to list everything that has ever been a vertebrate in 455 pages? Is he able to go into much detail beyond simply listing names?

What little I know I got from the Sues/Fraser book “Triassic Life on Land”. At maybe 20 years old, it’s already aging rapidly thanks to today’s ridiculous pace of discoveries.

[erik simpson]

Not every vertebrate, for sure. Not even every genus, but probably all of the better known "kinds" get at least a mention. The present
rate of new discoveries makes dents in any book's currency in about ten years.

[erik simpson]

The Paleocene resembles the Triassic with respect to the appearance of weird beasts that don't last
long in the evolutionary sense. For that matter, the same can be said for any rapid expansion into
new or recently vacated ecospace. The first arrivals in new territory got out of the blocks fast, but
may not be particularly well-adapted to conditions. For a glimpse of the strangness, have a look at
http://palaeos.com/cenozoic/paleocene/paleocene.html

[Sight Reader]

Wow, I might have to get that book!

Certainly a lot of these guys fall under the “fast-but-inefficient” category; however, we also have that end-Triassic extinction that may have wiped out a lotta guys that were doing perfectly well. From what I recall, our Triassic information is so sparse that it would be hard to tell exactly how long some of these weird experiments persisted.

[erik simpson]

I forget: did I recommend Brusatte's two books (The Rise and Fall of the Dinosaurs" and "The Rise
and Reign of the Mammals"? Brusatte's a great story teller as well as a very active paleontologist,
and goes into a lot of detail about the beginnings of these groups. Highly recommended.

[Peter Nyikos]

On Sunday, September 24, 2023 at 12:50:48 AM UTC-4, erik simpson wrote:
> On Saturday, September 23, 2023 at 9:04:14 AM UTC-7, erik simpson wrote:
> > On Friday, September 22, 2023 at 6:43:12 PM UTC-7, Peter Nyikos wrote:
> > > I've long been familiar with some strange critters of the Triassic, but I was
> > > really amazed at the variety that was displayed for us by Gary Meany, in Quora, of all places:
> > > https://www.quora.com/What-is-the-most-interesting-period-in-the-ancient-history-of-Earth-Is-it-the-Triassic-the-Jurassic-the-Cambrian-the-Devonian-or-other/answer/Gary-Meaney?ch=10&oid=274867839&share=f557083a&srid=pChjI&target_type=answer
> > >
> > > He starts out:
> > > "It’s like choosing a favourite child, honestly, but I think I’ll go with the Triassic for today. This period started about 251 million years ago, immediately preceded by the infamous End-Permian Extinction - the most devastating extinction event in Earth’s history.
> > >
> > > "The cause of this mass extinction, also known as the Great Dying, is debated, but we do know it was immensely lethal. It’s thought that nearly 60% of all biological families were wiped out, including 70% of the world’s land vertebrate species. What this means is that, entering the Triassic, evolution practically had a clean slate to experiment with."
> > >
> > >
> > > Then the fun begins: one unusual animal after another, each one with a well-executed color picture. Some I was familiar with:
> > >
> > > *Tanystropheus,* with a giraffe-like neck with a few long bones, attached to a simple lizard-like body;
> > >
> > > *Longisquama,* sporting a double row of long feather-like objects along its back;
> > >
> > > *Sharovipteryx,* with legs much longer than its arms, but with a glidiing membrane
> > > attached to its legs and the proximal part of its tail; and no gliding membrane elsewhere;
> > >
> > > *Desmatosuchus*, "a herbivore built like a tank. It bore a striking resemblance to the ankylosaurs, dinosaurs which only evolved long after this reptile went extinct."

By the way, this is not a complete list of what I recognized, but these four were
the most unusual IMO, and I didn't want to make my OP too long.

> > > But the list stretches on and on, with many another weird creature that I've never heard of before. A few of them:
> > >
> > > The archosaur *Erythrosuchus*, "which had a gigantic, bone-crushing head; proportionally, the largest of any known land vertebrate, extinct or otherwise."
> > >
> > > "*Scleromochlus*, a cross between a lizard and a kangaroo. Its back legs were long and springy, enabling it to move around by hopping."
> > >
> > > Marine reptiles included:
> > > "*Atopodentatus, a hilariously odd creature which had a flat, hammer-shaped head. It used this to sieve through the sediment, like an underwater vacuum cleaner."
> > >
> > > " The as of yet unnamed Lilstock Ichthyosaur. Discovered in 2018, this species may have been the largest reptile of all time, measuring a staggering 26 metres in length. Some argue it could even be comparable in size to the modern blue whale, but the evidence of this is shaky."
> > >
> > >
> > > As the saying goes, though, a picture is worth a thousand words, and I think it best to stop here
> > > and to let readers have the pleasure of going through the seemingly never-ending pictures for themselves.

> > Amazing bestiary. I'll be tracking down references for a while. I've known of some of them, but there are
> > several new to me.
> I've found that the reason I recalled some of these beasts is that they almost all appear in Prothero's "Vertebrate Evolution",

The pictures, or just the critters themselves?

> which I've mostly read. (Having a capricious memory, I can't begin to claim to have all, or even most of the information
> presented in that text in hand.). Prothero's text isn't to be compared to Romer's magisterial (but sadly now out of date) compendium,

nor to Carroll's magisterial, totally newly designed 1988 compendium, also sadly out of date.

And this time, there seems to be no worthy successor to these two great texts
on the horizon. Benton (not to be confused with Denton) has a nice succession of texts,
but alas,

Benton : Carroll :: Colbert : Romer

... in the sense of being much skimpier, though keeping up to date.

[Colbert's 1955 _Evolution_of_the_Vertebrates_ was about half as long as the 1945 version
of Romer's text, and I assume Romer's 1967 edition of _Vertebrate _Paleontology_ was
a minor update of what was in Romer's 1945 edition, and incorporating Colbert's additional data.]

> but it's more approachable, particular for amateurs.

Not having seen it, I can't comment.

Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--

Univ. of South Carolina at Columbia
http://people.math.sc.edu/nyikos

[erik simpson]

Some of the pictures are the same as those appearing in Prothero's book. Hint: any picture with a
blue woman's figure in it. The intent of Prothero's book is certainly different from Romer's. "Vertebrate
Paleontology" and "Vertebrate Evolution" shows the different emphasis. Romer goes into the kind
of detail hardly any book does these days. Details are to be found in the references. As I've remarked,
the effort of writing a book with the knowledge that it won't be all the long before the "out of date"
phrase appears makes it a wonder that any books get written.

[Peter Nyikos]

On Monday, September 25, 2023 at 11:26:21 AM UTC-4, erik simpson wrote:
> On Sunday, September 24, 2023 at 8:12:23 AM UTC-7, Sight Reader wrote:
> > On Saturday, September 23, 2023 at 10:50:48 PM UTC-6, erik simpson wrote:
> > > On Saturday, September 23, 2023 at 9:04:14 AM UTC-7, erik simpson wrote:
> > > > On Friday, September 22, 2023 at 6:43:12 PM UTC-7, Peter Nyikos wrote:
> > > > > I've long been familiar with some strange critters of the Triassic, but I was
> > > > > really amazed at the variety that was displayed for us by Gary Meany, in Quora, of all places:
> > > > > https://www.quora.com/What-is-the-most-interesting-period-in-the-ancient-history-of-Earth-Is-it-the-Triassic-the-Jurassic-the-Cambrian-the-Devonian-or-other/answer/Gary-Meaney?ch=10&oid=274867839&share=f557083a&srid=pChjI&target_type=answer
> > > > >
> > > > > He starts out:
> > > > > "It’s like choosing a favourite child, honestly, but I think I’ll go with the Triassic for today. This period started about 251 million years ago, immediately preceded by the infamous End-Permian Extinction - the most devastating extinction event in Earth’s history.
> > > > >
> > > > > "The cause of this mass extinction, also known as the Great Dying, is debated, but we do know it was immensely lethal. It’s thought that nearly 60% of all biological families were wiped out, including 70% of the world’s land vertebrate species. What this means is that, entering the Triassic, evolution practically had a clean slate to experiment with."
> > > > >
> > > > >
> > > > > Then the fun begins: one unusual animal after another, each one with a well-executed color picture.

<big snip for focus>

> > > I've found that the reason I recalled some of these beasts is that they almost all appear in Prothero's "Vertebrate Evolution",
> > > which I've mostly read. (Having a capricious memory, I can't begin to claim to have all, or even most of the information
> > > presented in that text in hand.). Prothero's text isn't to be compared to Romer's magisterial (but sadly now out of date)
> > > compendium, but it's more approachable, particular for amateurs.

> > Good Lord! Are you saying that this Prothero book is actually able to list everything that has ever been a vertebrate in 455 pages? Is he able to go into much detail beyond simply listing names?

Since I haven't seen it, I wish you had answered Sight Reader's questions in detail.

The obvious answer to the second question is "No, otherwise it would be *less*
approachable than Romer's text, particularly for amateurs."

Romer's 1945 text was already 687 pages long, but the classification starts at
page 573 and ends on p. 627. He says the list of genera known from fossils
is "comprehensive (although by no means complete)" whatever that means.

> > What little I know I got from the Sues/Fraser book “Triassic Life on Land”. At maybe 20 years old, it’s already aging rapidly thanks to today’s ridiculous pace of discoveries,

> The Paleocene resembles the Triassic with respect to the appearance of weird beasts that don't last
> long in the evolutionary sense. For that matter, the same can be said for any rapid expansion into
> new or recently vacated ecospace. The first arrivals in new territory got out of the blocks fast, but
> may not be particularly well-adapted to conditions. For a glimpse of the strangness, have a look at
> http://palaeos.com/cenozoic/paleocene/paleocene.html

A disappointment. Except for one color picture that ranks with the best of Gary Meany's,
it shows some amateurish outline drawings that even I could have drawn, and they
give almost no hint of the variety.

No mesonychids, no tillodonts, no early primatoforms, no marsupials
except for a suspicious opossum-lookalike in the one color picture.
The close resemblance reminds me of how Life Magazine's
colorful bestiary in the 1953 issue, "The Age of Mammals," included a Paleocene dermopteran,
*Planetetherium*, that looked exactly like a modern day colugo gliding through the air. But look:

"There is no direct evidence that Planetetherium had the membrane of skin that allows modern colugos to glide, but its bodily proportions suggests that this was likely the case.[2]"
-- https://en.wikipedia.org/wiki/Planetetherium

Reference [2] hardly inspires confidence:

Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 210. ISBN 1-84028-152-9.

Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--

Univ. of South Carolina in Columbia
http://people.math.sc.edu/nyikos

[Sight Reader]

On Monday, September 25, 2023 at 3:26:33 PM UTC-6, erik simpson wrote:
> (snip for length)

> I forget: did I recommend Brusatte's two books (The Rise and Fall of the Dinosaurs" and "The Rise
> and Reign of the Mammals"? Brusatte's a great story teller as well as a very active paleontologist,
> and goes into a lot of detail about the beginnings of these groups. Highly recommended.

I’m not sure if you did, but without a doubt, Brusatte appears to be one of few paleontologist around who seems to have both a genuine interest in engaging the layman and at least some teaching ability (including, at the very minimum, at least DEFINING terminology before using it, lol). I think, at the moment, he is a layman’s best hope for making the jump from pop science to technical literature (short of taking an undergraduate course, of course).

[Peter Nyikos]

On Saturday, September 23, 2023 at 1:34:54 PM UTC-4, Sight Reader wrote:
> On Friday, September 22, 2023 at 8:39:48 PM UTC-6, John Harshman wrote:
> <snip original post>
> > Fascinating site. I do have to wonder how much in the reconstructions is
> > based on actual material. I would also like to see more phylogenetic
> > context. I think some of the beaked reptiles are rhynchosaurs, but I'm
> > not sure. And there's as least one incorrect fact: Gerrothorax was a
> > temnospondyl, not a reptile. Still, interesting.


> Hmm… he must have repaired that Gerrothorax reference as it now shows up right after the temnospondyls Trematosaurus and Mastodonsaurus.

Wrong. Take a look at the comments section. Every comment is 2 years old. And I distinctly
recall the caption under Gerrothorax from before I posted the OP:

"Gerrothorax, an incredibly bizarre creature. Flat as a pancake, it would have hidden on riverbeds, its upward-facing eyes watching for prey. When a victim approached, its jaw would open upwards and create a huge suction force through its gills (yes, it had gills)."

https://www.quora.com/What-is-the-most-interesting-period-in-the-ancient-history-of-Earth-Is-it-the-Triassic-the-Jurassic-the-Cambrian-the-Devonian-or-other/answer/Gary-Meaney

Ain't no amniote with gills. John was his usual hasty self, posting less than an hour
after I posted the OP, and didn't bother to read all the captions.

> I’m thinking he deliberately avoided phylogenetic terms to keep from scaring away laymen testing out their interest in the topic.

I don't think so. Note the following comment:

"Understandably, when talking about the Triassic, the reptiles tend to take the spotlight. However, there were many other fascinating species around during this time. First of all, there were the synapsids - mammals and their relatives - such as:
Lisowicia, the largest non-mammalian synapsid of all time."

He goes along with the recent taxonomic fad of restricting "reptiles" to Sauropsida.
So much for all the old-timers who considered non-mammalian synapsids
to be "mammal-like reptiles."

And so much for all those who think the Permian was already part of the
Age of Reptiles. It wasn't sauropsids that dominated the Permian, it was
the synapsids: pelycosaurs and therapsids.

> He does have Hyperodapedon in there who would be your “classic” beaked rhynchosaur.

Good catch, Sight Reader.

>Beyond that, I would guess that too many weird new guys - some of whom could very well have beaks - keep popping up in that “protorosaur” tree to say who’s related to what. Didn’t that whole “allokotosaur” subtree, for instance, only come into focus a decade or so ago?

I was alerted to another sizable clade I'd never heard of before, the "Poposauroidea,"
a subtree of Pseudosuchia, by a fine addition to Meany's menagerie:

"In addition to the wonderful creatures that you have listed, there was another called Arizonasaurus. It looked like a smaller version of the Spinosaurus though completely unrelated and lived sometime in the mid Triassic." -- Vishak Athreya


This was way down in the comments section. It's well worth clicking on "View more comments"
once or twice to see the great reproduction: much more detailed than the ones in
the Wikipedia entry for this "Arizona lizard."

Peter Nyikos
Professor, Dept. of Mathematics

Univ. of South Carolina -- standard disclaimer--
http://people.math.sc.edu/nyikos

[Peter Nyikos]

This kind of talk belongs in talk.origins, not sci.bio.paleontology.


On the other hand, it IS legitimate sbp talk to ask whether this huge variety
of critters could be accounted for using just "random mutation and
competition within populations." A much more appealing idea is that, with so many
environments devoid of "harvesters" (including carnivores "harvesting" other animals)
it was a perfect time for an explosion of Punctuated Equilibrium (PE).

Small breakaway groups from flourishing populations could explore new niches,
and undergo rapid mutation favoring e.g. those bold enough to try novel foods.
Isolation from other small populations in new environments would result in mutations
affecting different groups differently, and these groups in turn would fragment
into others as they spread far and wide thru the continents.


John Harshman dislikes the whole idea of PE. I wonder what he would say to all this.

Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--

University of So. Carolina at Columbia
http://people.math.sc.edu/nyikos

[John Harshman]

I don't dislike the idea. I just don't think the evidence favors it. I'm
not sure you understand what PE is supposed to be either. You seem to be
adding a lot of extra baggage to it.

What you seem to be describing above doesn't require PE, just ordinary
within-species processes. You seem to be talking about release from
selection and the "empty barrel" idea of recovery from mass extinction.
Anyone can do this, not just small breakaway groups (peripheral
isolates). Anything that divides populations, potentially resulting in
speciation, is good enough. Nor is there any need or reason for
increased mutation rates.

What you may be groping toward is the idea of interspecific competition
as an evolutionary force. But competition that acts on selectable
variation within species is just standard population genetics, one
species acting as part of another's environment. Competition for which
there is no within-species selectable variation, however, can result in
differential extinction, or species selection, and that's not standard
population genetics.

[John Harshman]

On 9/27/23 6:52 PM, Peter Nyikos wrote:

This thread appears to have died. Not sure why.

[Sight Reader]

Well, at least on my end, all my major questions got answered, I walked away with more to think about, a greater sense of wonder, and perfectly happy to have participated in it, so there wasn’t a need to reply further.

[Peter Nyikos]

What do you think the following statement by Stephen Jay Gould is about?
Chopped liver?

"The extreme rarity of transitional forms in the fossil record
persist as the trade secret of paleontology. The evolutionary
trees that adorn our textbooks have data only at the tips and
nodes of their branches; the rest is inference, however reasonable,
not the evidence of fossils.
--Stephen J. Gould - "Evolution's Erratic Pace," _Natural History_,
vol. 86(5) (May 1987): pp. 12-16, at p. 14
Reprinted in _The Panda's Thumb_, pp. 181-182.
http://www.talkorigins.org/faqs/quotes/mine/part3.html#quote3.2

The above quote continued:

"Yet Darwin was so wedded to gradualism that he wagered his entire theory
on a denial of this literal record:

`The geological record is extremely imperfect and
this fact will to a large extent explain why we
do not find interminable varieties, connecting
together all the extinct and existing forms of life
by the finest graduated steps. He who rejects these views
on the nature of the geological record, will rightly reject
my whole theory.'

"Darwin's argument still persists as the favored escape of most
paleontologists from the embarrassment of a record that seems to show
so little of evolution [directly]. In exposing its cultural and
methodological roots, I wish in no way to impugn the potential
validity of gradualism (for all general views have similar roots).
I only wish to point out that it is never "seen" in the rocks."
[END OF QUOTE]

"never" is a tad harsh, but the horse superfamily Equioidea is one of
a mere handful of exceptions.

> I'm not sure you understand what PE is supposed to be either. You seem to be
> adding a lot of extra baggage to it.

But you won't tell us what allegedly makes me "seem" that way, eh?

More later this week. Duty calls.

Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--

University of So. Carolina in Columbia
http://people.math.sc.edu/nyikos

[John Harshman]

There are a number of problems with the statement. For one thing, Gould
didn't understand phylogenetics very well. For another, he's attacking a
strawman, something assumed neither by Darwin nor by population
geneticists or other evolutionary biologists, i.e. "phyletic gradualism".

Is it? Is the fossil record of horses so continuous as to show gradual
transitions from one species to the next? Gould here is again presenting
a strawman fossil record. Darwin was right: the fossil record is
fragmentary both in space and in time. There are few if any continuous
records over thousands or millions of years. And if we agree, with
Darwin, that evolution is episodic, periods of change being
comparatively rapid and few compared with periods of no change, then the
fragments we have are indeed unlikely to show those periods.

>> I'm not sure you understand what PE is supposed to be either. You seem to be
>> adding a lot of extra baggage to it.
>
> But you won't tell us what allegedly makes me "seem" that way, eh?

You snipped out the entire explanation, I assume inadvertently. Let me
restore it for you:

[Peter Nyikos]

On Wednesday, October 18, 2023 at 11:10:53 PM UTC-4, John Harshman wrote:
> On 10/18/23 7:07 PM, Peter Nyikos wrote:
> > On Wednesday, October 4, 2023 at 2:43:59 PM UTC-4, John Harshman wrote:
> >> On 9/27/23 6:52 PM, Peter Nyikos wrote:


> >>> On the other hand, it IS legitimate sbp talk to ask whether this huge variety
> >>> of critters could be accounted for using just "random mutation and
> >>> competition within populations." A much more appealing idea is that, with so many
> >>> environments devoid of "harvesters" (including carnivores "harvesting" other animals)
> >>> it was a perfect time for an explosion of Punctuated Equilibrium (PE).
> >>>
> >>> Small breakaway groups from flourishing populations could explore new niches,
> >>> and undergo rapid mutation favoring e.g. those bold enough to try novel foods.
> >>> Isolation from other small populations in new environments would result in mutations
> >>> affecting different groups differently, and these groups in turn would fragment
> >>> into others as they spread far and wide thru the continents.
> >>>
> >>>
> >>> John Harshman dislikes the whole idea of PE. I wonder what he would say to all this.
> >
> >> I don't dislike the idea. I just don't think the evidence favors it.
> >
> > What do you think the following statement by Stephen Jay Gould is about?
> > Chopped liver?

John, you prefaced what I quoted with the following:

> There are a number of problems with the statement. For one thing, Gould
> didn't understand phylogenetics very well.

Is this going to be a fixture of your posting, making put-downs
like this without explanation?

> > "The extreme rarity of transitional forms in the fossil record
> > persist as the trade secret of paleontology. The evolutionary
> > trees that adorn our textbooks have data only at the tips and
> > nodes of their branches; the rest is inference, however reasonable,
> > not the evidence of fossils.
> > --Stephen J. Gould - "Evolution's Erratic Pace," _Natural History_,
> > vol. 86(5) (May 1987): pp. 12-16, at p. 14
> > Reprinted in _The Panda's Thumb_, pp. 181-182.
> > http://www.talkorigins.org/faqs/quotes/mine/part3.html#quote3.2
> >
> > The above quote continued:
> >
> > "Yet Darwin was so wedded to gradualism that he wagered his entire theory
> > on a denial of this literal record:
> >
> > `The geological record is extremely imperfect and
> > this fact will to a large extent explain why we
> > do not find interminable varieties, connecting
> > together all the extinct and existing forms of life
> > by the finest graduated steps. He who rejects these views
> > on the nature of the geological record, will rightly reject
> > my whole theory.'


> For another, he's attacking a
> strawman, something assumed neither by Darwin nor by population
> geneticists or other evolutionary biologists, i.e. "phyletic gradualism".

What, then do you make of the words, "by the finest graduated steps"?
You don't say. Another unexplained put-down.

If Kerr-Mudd returns to this thread, what are the odds that
he will NOT reply to you, but to me with the claim that he dislikes
this kind of talk?

> >
> > "Darwin's argument still persists as the favored escape of most
> > paleontologists from the embarrassment of a record that seems to show
> > so little of evolution [directly]. In exposing its cultural and
> > methodological roots, I wish in no way to impugn the potential
> > validity of gradualism (for all general views have similar roots).
> > I only wish to point out that it is never "seen" in the rocks."
> > [END OF QUOTE]
> >
> > "never" is a tad harsh, but the horse superfamily Equioidea is one of
> > a mere handful of exceptions.

> Is it? Is the fossil record of horses so continuous as to show gradual
> transitions from one species to the next?

The one from early Merychippus species to Dinohippus is said
to be like that, in:

http://www.talkorigins.org/faqs/horses/horse_evol.html
Excerpt:
3. A line of "true equines" in which the side toes sometimes began to decrease in size. In this flurry of evolution, Merychippus primus gave rise to two later merychippines called M. sejunctus and M. isonesus, who had a mixture of "primitive" (Parahippus-like), hipparion, and equine features. They, in turn, gave rise to M. intermontanus, which begat M. stylodontus and M. carrizoensis. These last two looked quite "horsey" and gave rise to a set of larger three-toed and one-toed horses known as the "true equines" (see below). Crystal clear, right?

>Gould here is again presenting
> a strawman fossil record.

Your subsequent comments do not support this latest put-down. Were you shooting from the hip,
without consulting his article? You do have a copy of _The Panda's Thumb_, don't you?

> Darwin was right: the fossil record is
> fragmentary both in space and in time.

No kidding, Sherlock.

Gould confirmed that in the above linked article, and said
that PE made the details conform better to the existing evidence.

> There are few if any continuous
> records over thousands or millions of years.

You are confirming Gould's words,

[repeated from above]

> > I wish in no way to impugn the potential
> > validity of gradualism (for all general views have similar roots).
> > I only wish to point out that it is never "seen" in the rocks."

> And if we agree, with
> Darwin,

And with Gould,

> that evolution is episodic, periods of change being
> comparatively rapid and few compared with periods of no change, then the
> fragments we have are indeed unlikely to show those periods.

And Gould and his less well-known coauthor, Niles Eldredge, have an explanation that
further elucidates that unlikeliness.


Concluded in next reply, soon after I see that this one has been posted.

Peter Nyikos
Professor, Dept. of Mathematics

University of So. Carolina -- standard disclaimer--
http://people.math.sc.edu/nyikos

[Peter Nyikos]

On Wednesday, October 18, 2023 at 11:10:53 PM UTC-4, John Harshman wrote:
> On 10/18/23 7:07 PM, Peter Nyikos wrote:
> > On Wednesday, October 4, 2023 at 2:43:59 PM UTC-4, John Harshman wrote:

> >> I'm not sure you understand what PE is supposed to be either. You seem to be
> >> adding a lot of extra baggage to it.
> >
> > But you won't tell us what allegedly makes me "seem" that way, eh?


> You snipped out the entire explanation, I assume inadvertently.

No, it was because you made no effort to explain it, and only a sketchy attempt
to explain your first sentence.

> Let me
> restore it for you:
> What you seem to be describing above doesn't require PE, just ordinary
> within-species processes.

It's not a question of "requiring," but only a question of whether
PE is a better explanation than the one you give:

> You seem to be talking about release from
> selection

Certainly a reduction, with exploding sources of nourishment,
with or without speciation in the sources.

> and the "empty barrel" idea of recovery from mass extinction.
> Anyone can do this, not just small breakaway groups (peripheral
> isolates).

The issue is whether breakaway isolates is a better explanation
for such a massive radiation. It certainly seems to work better
in times of reduced radiation.

And note, I'm not adding baggage to PE. I am adding PE to
"empty barrell" recovery. You may call this excess baggage,
but you need to make a separate case for that.

> Anything that divides populations, potentially resulting in
> speciation, is good enough. Nor is there any need or reason for
> increased mutation rates.

I was pressed for time, as usual, and was abrupt.
What I meant was increased rates of survival
of novel mutations due to increased ability to process exploding
food sources. These sources would have not helped
them earlier, when they were at a disadvantage
against the ones using the plentiful pre-catastrophe food sources.

> What you may be groping toward is the idea of interspecific competition
> as an evolutionary force.

So far from groping, I was talking about one of my favorite topics:
mega-competition between big clades. I did it wrt competition between
between pterosaurs and birds, on the thread "Triassic Mega-Evolution."
Sight Reader then provided a very promising possibility of
rynchocephalians v. squamates on Oct. 4.

This was before you started posting on this thread.


After this, you went off on a tangent ["derailing the thread" is
the way you put it if I do it] on population genetics:

> But competition that acts on selectable
> variation within species is just standard population genetics, one
> species acting as part of another's environment.

"another's" gives the game away. Each species of pterosaur was
competing with many species of birds, and vice versa.
There were lots of other potential cases in the Triassic.

> Competition for which
> there is no within-species selectable variation, however, can result in
> differential extinction, or species selection, and that's not standard
> population genetics.

So, why bring population genetics into the picture at all?

Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--

Univ. of So. Carolina at Columbia
http://people.math.sc.edu/nyikos

[John Harshman]

On 10/20/23 8:22 AM, Peter Nyikos wrote:
> On Wednesday, October 18, 2023 at 11:10:53 PM UTC-4, John Harshman wrote:
>> On 10/18/23 7:07 PM, Peter Nyikos wrote:
>>> On Wednesday, October 4, 2023 at 2:43:59 PM UTC-4, John Harshman wrote:
>>>> On 9/27/23 6:52 PM, Peter Nyikos wrote:
>
>
>>>>> On the other hand, it IS legitimate sbp talk to ask whether this huge variety
>>>>> of critters could be accounted for using just "random mutation and
>>>>> competition within populations." A much more appealing idea is that, with so many
>>>>> environments devoid of "harvesters" (including carnivores "harvesting" other animals)
>>>>> it was a perfect time for an explosion of Punctuated Equilibrium (PE).
>>>>>
>>>>> Small breakaway groups from flourishing populations could explore new niches,
>>>>> and undergo rapid mutation favoring e.g. those bold enough to try novel foods.
>>>>> Isolation from other small populations in new environments would result in mutations
>>>>> affecting different groups differently, and these groups in turn would fragment
>>>>> into others as they spread far and wide thru the continents.
>>>>>
>>>>>
>>>>> John Harshman dislikes the whole idea of PE. I wonder what he would say to all this.
>>>
>>>> I don't dislike the idea. I just don't think the evidence favors it.
>>>
>>> What do you think the following statement by Stephen Jay Gould is about?
>>> Chopped liver?
>
> John, you prefaced what I quoted with the following:
>
>> There are a number of problems with the statement. For one thing, Gould
>> didn't understand phylogenetics very well.
>
> Is this going to be a fixture of your posting, making put-downs
> like this without explanation?

Was one needed? Gould seldom, if ever, discussed phylogenetic analysis,
and that quote shows that lack of knowledge when he says, as if it's
pejorative, that fossils are only at the tips of trees.

>>> "The extreme rarity of transitional forms in the fossil record
>>> persist as the trade secret of paleontology. The evolutionary
>>> trees that adorn our textbooks have data only at the tips and
>>> nodes of their branches; the rest is inference, however reasonable,
>>> not the evidence of fossils.
>>> --Stephen J. Gould - "Evolution's Erratic Pace," _Natural History_,
>>> vol. 86(5) (May 1987): pp. 12-16, at p. 14
>>> Reprinted in _The Panda's Thumb_, pp. 181-182.
>>> http://www.talkorigins.org/faqs/quotes/mine/part3.html#quote3.2
>>>
>>> The above quote continued:
>>>
>>> "Yet Darwin was so wedded to gradualism that he wagered his entire theory
>>> on a denial of this literal record:
>>>
>>> `The geological record is extremely imperfect and
>>> this fact will to a large extent explain why we
>>> do not find interminable varieties, connecting
>>> together all the extinct and existing forms of life
>>> by the finest graduated steps. He who rejects these views
>>> on the nature of the geological record, will rightly reject
>>> my whole theory.'
>
>
> > For another, he's attacking a
>> strawman, something assumed neither by Darwin nor by population
>> geneticists or other evolutionary biologists, i.e. "phyletic gradualism".
>
> What, then do you make of the words, "by the finest graduated steps"?
> You don't say. Another unexplained put-down.

I'm trying to excuse your ignorance of this subject after many years of
claiming some knowledge of the field. But PE is not a theory of
saltation, as you seem to think. It in fact involves evolution by finely
graduated steps, just at different rates at different times, as opposed
to the Gouldian strawman of a constant rate. The original Phacops rana
example is just such a series of fine steps. Have you even read Eldredge
and Gould 1972?

> If Kerr-Mudd returns to this thread, what are the odds that
> he will NOT reply to you, but to me with the claim that he dislikes
> this kind of talk?

I see no reason to speculate.

>>> "Darwin's argument still persists as the favored escape of most
>>> paleontologists from the embarrassment of a record that seems to show
>>> so little of evolution [directly]. In exposing its cultural and
>>> methodological roots, I wish in no way to impugn the potential
>>> validity of gradualism (for all general views have similar roots).
>>> I only wish to point out that it is never "seen" in the rocks."
>>> [END OF QUOTE]
>>>
>>> "never" is a tad harsh, but the horse superfamily Equioidea is one of
>>> a mere handful of exceptions.
>
>> Is it? Is the fossil record of horses so continuous as to show gradual
>> transitions from one species to the next?
>
> The one from early Merychippus species to Dinohippus is said
> to be like that, in:
>
> http://www.talkorigins.org/faqs/horses/horse_evol.html
> Excerpt:

> 3. A line of "true equines" in which the side toes sometimes began to
> decrease in size. In this flurry of evolution, Merychippus primus
> gave rise to two later merychippines called M. sejunctus and M.
> isonesus, who had a mixture of "primitive" (Parahippus-like),
> hipparion, and equine features. They, in turn, gave rise to M.
> intermontanus, which begat M. stylodontus and M. carrizoensis. These
> last two looked quite "horsey" and gave rise to a set of larger
> three-toed and one-toed horses known as the "true equines" (see
> below). Crystal clear, right?

Yes, but not the sort of thing demanded by "phyletic gradualism".
Remember, PE was intended to explain the observed lack of gradual
transition between species. Here you have a series of species, which is
not what Gould and Eldredge mean by "gradualism".

> >Gould here is again presenting
>> a strawman fossil record.
>
> Your subsequent comments do not support this latest put-down. Were you shooting from the hip,
> without consulting his article? You do have a copy of _The Panda's Thumb_, don't you?

You fundamentally misunderstand the nature of the controversy here. It
would take a very long time to correct you, especially when you assume
that I'm the one who doesn't understand.

>> Darwin was right: the fossil record is
>> fragmentary both in space and in time.
>
> No kidding, Sherlock.
>
> Gould confirmed that in the above linked article, and said
> that PE made the details conform better to the existing evidence.

The problem here is that the fragmentary fossil record is itself an
explanation for the lack of smooth transitions, especially if periods of
change are episodic and relatively brief. No need for a special mechanism.

>> There are few if any continuous
>> records over thousands or millions of years.
>
> You are confirming Gould's words,

Yet neither you nor Gould seems to understand that those words argue
against a need for PE to explain the data.

> [repeated from above]
>>> I wish in no way to impugn the potential
>>> validity of gradualism (for all general views have similar roots).
>>> I only wish to point out that it is never "seen" in the rocks."
>
>> And if we agree, with
>> Darwin,
>
> And with Gould,

Yes, but not with Gould's strawman version of Darwin. That's my point.

>> that evolution is episodic, periods of change being
>> comparatively rapid and few compared with periods of no change, then the
>> fragments we have are indeed unlikely to show those periods.
>
> And Gould and his less well-known coauthor, Niles Eldredge, have an explanation that
> further elucidates that unlikeliness.

It's an unnecessary explanation, as it adds nothing. We could discuss
the problems of PE as a theory of evolution, but I have doubts that you
are equipped.

[John Harshman]

On 10/20/23 9:10 AM, Peter Nyikos wrote:
> On Wednesday, October 18, 2023 at 11:10:53 PM UTC-4, John Harshman wrote:
>> On 10/18/23 7:07 PM, Peter Nyikos wrote:
>>> On Wednesday, October 4, 2023 at 2:43:59 PM UTC-4, John Harshman wrote:
>
>>>> I'm not sure you understand what PE is supposed to be either. You seem to be
>>>> adding a lot of extra baggage to it.
>>>
>>> But you won't tell us what allegedly makes me "seem" that way, eh?
>
>
>> You snipped out the entire explanation, I assume inadvertently.
>
> No, it was because you made no effort to explain it, and only a sketchy attempt
> to explain your first sentence.

You really shouldn't snip explanations, no matter how inadequate, and
then complain that there was no explanation. Do you really not see the
problem here?

>> Let me
>> restore it for you:
>> What you seem to be describing above doesn't require PE, just ordinary
>> within-species processes.
>
> It's not a question of "requiring," but only a question of whether
> PE is a better explanation than the one you give:

That's what "requiring" means.

>> You seem to be talking about release from
>> selection
>
> Certainly a reduction, with exploding sources of nourishment,
> with or without speciation in the sources.
>
>
>> and the "empty barrel" idea of recovery from mass extinction.
>> Anyone can do this, not just small breakaway groups (peripheral
>> isolates).
>
> The issue is whether breakaway isolates is a better explanation
> for such a massive radiation. It certainly seems to work better
> in times of reduced radiation.

Not sure why you think so. What's your evidence that peripheral isolates
are important in speciation, as a general rule? If you want to know
something about speciation, I recommend the book Speciation, by Jerry
Coyne and H. Allen Orr. It's a few years old, but it's accessible to an
educated reader, and you should be able to find it at any good library.

> And note, I'm not adding baggage to PE. I am adding PE to
> "empty barrell" recovery. You may call this excess baggage,
> but you need to make a separate case for that.

It's excess baggage because it contributes nothing to the story.
Ordinary allopatric speciation (as well as evolution within populations
without attendant speciation) is adequate.

Incidentally, the greatest weakness of PE is its claim that speciation
and evolutionary change are necessarily coincident.

>> Anything that divides populations, potentially resulting in
>> speciation, is good enough. Nor is there any need or reason for
>> increased mutation rates.
>
> I was pressed for time, as usual, and was abrupt.
> What I meant was increased rates of survival
> of novel mutations due to increased ability to process exploding
> food sources. These sources would have not helped
> them earlier, when they were at a disadvantage
> against the ones using the plentiful pre-catastrophe food sources.

Now I'm not sure what you're trying to say. You seem to be talking about
natural selection favoring certain adaptations in an altered
environment. But this also requires no new theory of evolution. But at
least we've agreed that mutation rate is not a serious variable here.

>> What you may be groping toward is the idea of interspecific competition
>> as an evolutionary force.
>
> So far from groping, I was talking about one of my favorite topics:
> mega-competition between big clades. I did it wrt competition between
> between pterosaurs and birds, on the thread "Triassic Mega-Evolution."
> Sight Reader then provided a very promising possibility of
> rynchocephalians v. squamates on Oct. 4.

You are inventing new terms that just disguise what you're actually
talking about: interspecific competition. Any competition isn't between
clades but between individual species. How does adding "mega-" to
various words clarify anything? I also point out that inferring such
competition from the fossil record is dubious at best.

> This was before you started posting on this thread.
>
>
> After this, you went off on a tangent ["derailing the thread" is
> the way you put it if I do it] on population genetics:
>
>
>> But competition that acts on selectable
>> variation within species is just standard population genetics, one
>> species acting as part of another's environment.
>
> "another's" gives the game away. Each species of pterosaur was
> competing with many species of birds, and vice versa.
> There were lots of other potential cases in the Triassic.

You have no way of knowing this, and at any rate it's not relevant to
the point. As long as there's selectable variation within the species,
it's just ordinary population genetics. As long as there isn't, it's
species selection, a term you may not be familiar with.

(Note: there is much argument in the literature over what counts as
species selection; some would not agree that this is and would call it
"species sorting" instead. I don't see the point.)

>> Competition for which
>> there is no within-species selectable variation, however, can result in
>> differential extinction, or species selection, and that's not standard
>> population genetics.
>
> So, why bring population genetics into the picture at all?

Because there are two cases, and you had not differentiated them. Still
haven't.