Talk:Pelycosaur

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Shouldn't the entry mention that pelycosaurs were mammal like reptiles?

No, because they weren't what is usually meant by the term. More properly, they were the line that led to the mammal-like reptiles, or Theraspids. CFLeon 07:47, 7 May 2006 (UTC)

At Synapsid Pelycosaurs and Theraspids are co-orders of the same class, so I've changed the article to say they are cousins. --Michael C. Price ^talk 10:32, 25 February 2008 (UTC)

Pelycosauria redefined

A new definition for Pelycosauria is here provided:

Pelycosauria Cope, 1878 New defintion - All synapsids closer to Eupelycosauria and Caseasauria than to basal Synapsida.

yes but Pelycosaurs are basal Synapsids; it's a paraphyletic group M Alan Kazlev 04:28, 26 August 2006 (UTC)

O.k. they're paraphyletic, No biggie. Keeps the taxon within sensible limits. Also its better to define a taxon (genus, family, order, etc) on observable characters rather than, more closely related to this than to that. J.H.McDonnell (talk) 00:57, 17 September 2010 (UTC)

Text contradicts illustration?

According to the text, the clade Eupelycosauria includes the Theraspids. Acoording to the taxonomy list, they are a sub-order of order Pelycosaur beside order Theraspida.

I get that there are competing systems out there, but someone should clean that up, at least a note or a comment. --Sukkoth 20:55, 27 September 2007 (UTC)

Unnecessary bother

It seems a lot of bother is made over clades which are based on a concept not all that difficult to understand. Clades of best used when evolutionary relationships are the issue, especially those which follow. When the concern is over a particular and well defined group, such as Pelycosaurs, the cladistic approach isn't particularly useful, if at all. In this case its better to think of them in the traditional sense as an ordinary taxon.

When it says "At least two pelycosaur clades independently evolved a tall sail, ..etc" it could have just as well have said: at least two pelycosauran families independently evolved a tall sail. For practical purposed in this case the two terms are interchangeable, except that clade is more ambiguous.

Just one man's perspective. Cheers J.H.McDonnell (talk) 00:51, 17 September 2010 (UTC)

comparison to Late Devonian extinction ??

The late Devonian extinction c.370Ma can be construed, as resulting from the fishes' evolution of jaws, and teeth, c.400Ma; fish then went on a global feeding frenzy, and gradually drove many other species extinct; so explaining the higher background-rate of (marine) extinction after 400Ma. A hundred million years later, the evolution of warm-blood, by basal Therapsids, may have been a similar "quantum leap" in evolution, causing a burst of Therapsid expansion across Pangea, which came at the expense, of more primitive species, who suffered Olson's Extinction c.270Ma. The article's reference to "late surviving forms" of Pelycosaurs, echoes similar statements for (even more primitive) Varanopidae, who also eked out survival, in then-arctic South Africa, until c.260Ma. Plausibly, warm-blooded Therapsids evolved an advanced(-for-earth) feature c.270Ma, which was then a "quantum leap" over contemporary species, even as eons earlier, jawed fish evolved an advanced feature. Perhaps such biogenic mass extinctions become less frequent, over evolutionary time, as more advanced features become more common? If so, then modern anthropogenic extinctions may be part of a persistent pattern, spanning nearly a half billion years, of "quantum advances" bringing about biogenic mass extinctions (not caused by geologic, or cosmologic, pheonomena). Contact with advanced species may have caused the late Devonian, and mid Permian, mass extinctions.66.235.38.214 (talk) 12:26, 22 October 2012 (UTC)

Help request: Two pelycosaur-related articles need work.

I have real-life limitations (see my user page if curious), but they're not at their worst right now, so why can't I figure out exactly what it is that is hurting my head about comparing the information in this article with that in the section Paraphyly#Paraphyly_cannot_be_based_on_independently_evolved_traits? Sigh.

Anyway, here are some improvements that I can suggest, although more (or different ones) are probably needed:

1. It would be great if the editor who improves this article would also work on the Paraphyly section that discusses pelycosaurs at the same time.
2. Before even thinking on how to improve the intro, I'd wrestle the rest of the article into shape and then let that shape guide me to redo the intro.
3. The intro's sentence, "Because more advanced groups of synapsids evolved directly from 'pelycosaurs', the term had fallen out of favor among scientists by the 21st century," is very confusing. Which term? What term if any term is now used in its stead? What changed? Did we always know that more advanced groups of synapsids &c., &c.? Is "evolved" or "directly" the more important word there? Were the terminology options clear-cut all of a sudden or was it gradual? 2 term options or more?
   Not all of my questions here need to be answered in a rewrite, but some at least should be to draw a clear connection between the two halves of this sentence.
4. Right now, all kinds of info is sprinkled throughout all kinds of sections. I'd separately clarify (although in what order, I don't know) the histories of the name/classification and the evolution of the animal, perhaps along these headings and subheadings:

• Development of the classification of Pelycosaurs

• Details of competing ideas
• Timeline of the classification development

• Pelycosaurs and evolutionary history

• The evolution of the pelycosaurs
• Pelycosaurs and the evolution of modern animals

I usually don't make it back to talk pages where I suggest things (which is why I have to capture my thoughts all at once or not at all), so please use WP:Notifications if you want to get my attention back to this page—and limitations allowing, I'll try to return. Thanks in advance! --Geekdiva (talk) 21:58, 3 November 2014 (UTC)

Pelycosaur Scales

The section "Description" claims that pelycosaurs lacked reptilian epidermal scales (without even a mildening "likely" or "possibly"). There are several problems with this.

Firstly, what evidence is there that pelycosaurs supposedly didn't have reptilian epidermal scales?

Secondly, the varanopid Ascendonanus nestleri did very much have reptilian epidermal scales, even within the range of not-mammalian and not-bird reptiles alive today and very like the scales of living lepidosauromorphs (see , especially pages 321, 322, and 358). This might be evidence for pelycosaurs (at least basal ones) having had reptilian epidermal scales. I'm saying "might" only because the position of the clade Varanopidae in the reptile family tree is uncertain; it may be more closely related to birds than to mammals after all.

Thirdly, a study conclusively demonstrates that mammal hair, reptile scales, and bird feathers are all homologous to each other by showing that living reptiles do in fact develop anatomical placodes just like mammals and birds do. It shows that the last shared forebear of mammals, living not-mammalian and not-bird reptiles, and birds had a kind of skin appendage from which hair, modern reptile scales, and feathers have evolved. Doesn't this suggest that pelycosaurs were indeed covered in reptilian epidermal scales?

Kniva Keisarabani the Goth (talk) 08:10, 12 September 2020 (UTC)

I'm not a subject matter expert and I'm not going to try to resolve this. But the statement does seem poorly sourced, possibly involving WP:OR or WP:SYNTHESIS. The editor seems to have extrapolated from the presence of osteoderms mentioned in the cited source to the conclusion that pelycosaurs had no reptilian epidermal scales, but Wikipedia's article on osteoderms says they are widespread in modern reptiles.

Some possibly useful links I Googled up:

|1973 paper on evolution of hair follicles, suggesting pelycosaurs had scales but these had the beginnings of primitive hair follices in their hinge regions.

|Eupelycosaurid skin impression with scales.

That said: The original poster here is engaging in a fair amount of original research and synthesis himself. We need solid sourcing either way. Or, if the sources don't agree, we need to have this section of the article note that whether pelycosaurs had reptilian epidermal scales is still a matter of research. --Kent G. Budge (talk) 14:18, 30 October 2020 (UTC)

A recent study found that varanopids weren't even synapsids. The statements probably do need to be better worded Hemiauchenia (talk) 17:49, 30 October 2020 (UTC)

If synapsids could be shown not to have anything resembling lepidosaur scales, then it's yet another thing distinguishing them from 'reptiles'. It's an ongoing crusade, just like saying 'radiodont arthropod' instead of plain 'radiodont'. 161.230.125.227 (talk) 23:16, 15 April 2023 (UTC)

References