Talk:Therapsida

Intro paragraph needs to be altered

Tetraceratops is no longer considered to be a basal Therapsid according to the article Tetraceratops. I would change it myself, but I have no other references to support this. Can someone please confirm that this information is indeed correct? Bomb319 (talk) 16:42, 5 December 2020 (UTC)

UPDATE: I changed this information based on the reference , but if anyone knows this to be incorrect or can provide further information, it should be altered or reverted. Bomb319 (talk) 16:52, 5 December 2020 (UTC)

References

Could some word other than "Order" be used to name this taxon?

I am trying to list the entire lineage from Subspecies to Domain and now I have 2 lines named "Order". I'm confident this one is wrong.

I just had the same thought ... it does not make sense that the class ‘mammals’ is part of the ‘order’ ... McChrystal (talk) 10:50, 14 July 2018 (UTC)

Subclass, class, superclass

For lack of a better name, perhaps Therapsida should be placed in a taxon called a subsuperclass. What do you think? --Ingoolemo 01:22, 2004 Jun 13 (UTC)

It'd probably be better not to try to combine the Linnean and Cladistic systems in this way. The cladistic system has an indefinite number of branches; these aren't the same as the linnean hierarchies of Class, Phylum, etc. My own take (others may disagree) is that the cladistic phylogeny and linnean hierarchy are two distinct but complementary approaches to the classification of life.

For a generic cladistic taxonomic "rank" one can always say "plesion" (I think technically every clade is (or can be called) a "plesion") --M Alan Kazlev 23:31 (AEST), 2005 Feb 20

It would be very useful if someone could add the characteristics of Therapsida that distinguish it from other sub-clades of synapsida. When I google, all I find are some vague hints about "differences in posture". Vasi 11:12, 27 December 2005 (UTC)

I thought all therapsids became extinct at the end of the Triassic, and the taxobox said they made it into the Cretaceous. What therapsids existed then? Giant Blue Anteater 02:56, 20 June 2006 (UTC)

A number of non-mammalian therapsids lived into the Jurassic, and at least two genera (Xenocretosuchus and and unnamed form from Japan) lived into the EK.Dinoguy2 15:04, 20 June 2006 (UTC)

Rewrite needed

Not wishing to be rude to anyone but yesterday's rewrite of a large section of this article needs a 'going over' by someone who has reliable knowledge of the subject, so that sense is not lost in editing. I'd do it myself but I'm not confident enough on the factual side. Grammar and punctuation in need of a serious 'spring clean'. - Ballista 05:21, 13 September 2006 (UTC)

What are they?

In a fit of ignorance, I called these things dinosaurs. Somebody improved that by calling them reptiles. But the article (now that I've read it more closely) clarifies that they weren't exactly reptiles, either. What made me originally call them dinosaurs is that they are long extinct, and that fact wasn't mentioned in the lead. Now I've changed it so they are no longer "dinosaurs," or "reptiles," but merely "extinct." If somebody has something better, please have at it. Skyrocket654 (talk) 02:59, 10 February 2008 (UTC)

Over the years creatures have evolved so much that some creatures no longer fit the taxonomic definition we commonly go by nowadays. Are they reptiles simply due to resemblance, or are they already more like mammals with what we now identify as an important definition for what makes an animal a mammal?

I'm literally only here because I made a reptilian creature that is warm blooded in DnD so I could put it on a mountain. 134.83.3.176 (talk) 21:57, 16 March 2023 (UTC)

First, they are none of the above, they are the ancestors of what would become mammals, they are Synapsids. Second why was Neotherapsida redirected here.Ita like looking up FDR and being redirected to Theodore Roosevelt.(user cn761492920:14 PM 24 December 2024(UIC)71.38.212.201 (talk) 04:16, 25 December 2024 (UTC)

"Beliefs"

I was baffled by the appearance of "believed" in the introduction:

"Therapsids are an order of synapsids (Class Synapsida) that are believed to include mammals and their immediate evolutionary ancestors."

The category therapsids is not a matter of "believing" since it is a factual taxonomic category. I understand that there are editors (creationists and the like) around that may question the existence of the species within the category, but it is preposterous to call the category used to catalogue these theoretical species as something that you may believe exists. It exists in academia whether or not the species did.--Berig (talk) 14:09, 19 May 2009 (UTC)

Phylogenetic and traditional definitions

I propose we discuss new wording for the lede here, to avoid any edit wars. With a bit of patience and cooperation, we will probably be able to come up with a wording that cater to both sides, reflect phylogeny as far as is known and gives the article the scope we want. Petter Bøckman (talk) 18:45, 26 November 2011 (UTC)

How many published sources are represented in both "sides"? We should reflect consensus, not give equal time to fringe classifications. MMartyniuk (talk) 19:23, 26 November 2011 (UTC)

Feel free to define Benton as fringe. There should be possible to find a decent amount of textbooks (i.e. secondary sources) using traditional classification, as opposed to primary sources. As for the use of the term "Therapsida" in phylogenetic taxonomy, I find plenty of references to e.g. Gorgonops and Cynognathus as therapsids, but very, very few uses of Therapsida in connection with e.g. elephants, hedgehogs or sloths. The trend is very clear, the name is used for all (clade-) therapsids, except mammals. Thus, it is a clade in name only, for all practical purpose it is used as a grade. I haven't seen it published anywhere though, so it may be WP:OR Petter Bøckman (talk) 20:55, 26 November 2011 (UTC)

If a usage is only found in secondary sources by a handfull of researchers in the relevant fields, then I would classify it as fringe, just as Feduccia et al. are considered fringe when it comes to bird origins. I would certainly define Benton as finge when it comes to classification, because his taxonomy is not followed by a majority of other researchers. MMartyniuk (talk) 15:22, 27 November 2011 (UTC)

I'm not much of a fan of Benton's classification either, but it seems he has cornered the marked with regard to textbooks. And it is secondary sources we are supposed to follow. Petter Bøckman (talk) 21:45, 27 November 2011 (UTC)

I think the secondary sources guideline is stretched to the maximum when the only available secondary sources are all by a single researcher who uses them to promote his proprietary system that is far outside the norm for the field. A slightly more extreme analogy would be if all vert. paleo textbooks were written by Larry Martin, would wiki be obliged to classify birds as non-dinosaurian archosaurs? MMartyniuk (talk) 13:41, 28 November 2011 (UTC)

Therapsida is widely accepted as a clade, and there's little confusion over its use as a clade in scientific literature (unlike some other groups). Since it's a clade, mammals must be included. Phylogenetics can be confusing to laypeople, but it's better to follow it than to use a simpler pre-phylogenetic taxonomy. How's this for a lead: "Therapsida is a clade of synapsids including mammals and their immediate ancestors. The name is most commonly used to describe these ancestors, which resembled reptiles and were common in the Permian and Triassic periods." Smokeybjb (talk) 01:41, 28 November 2011 (UTC)

Re "The name is most commonly used to describe these ancestors", MMartyniuk just removed one of my edits saying just that (in a few more words) as "unreferenced". You observation is spot on, but it's our observation, so can we put in in WP?

What you have put your finger on is a problem in making phylogenetic taxonomy (actually any form of systematics) understandable to laypeople. I mean, what critters do you want to see covered under the heading "Therapsida"? I guess dicynodonts, Estemmenosuchus, Gorgonops, Thrinaxodon and a special mention of Trithelodon or some other very "near-mammal" critter? At least that's what I expect to find. The problem is that this selection is not at all representative of Therapsida as a clade. These are the non-mammalian therapsids. Any reasonable discussion of the clade should include a discussion of the reproductive strategies of monotrems, marsupials and placentals, the evolution of the ruminants, the size of Indricotherium, Blue whale and Etruscan shrew etc. But no, we want this article to be about therapsids, not mammals. We have had this exactly same discussion over at Dinosaurs.

The strange result of hard-line phylogenetic nomenclature is a situation where units are defines as clades, but used as grades. I've had the same problem with Tetrapoda, which some users of the more phylogenetic nomenclaturist bend have taken to use as a synonym for labyrinthodonts, because the latter is a grade and thus can not be used by them. The same goes for Synapsida. These units are "clades, only they are not really". This kind of double communication is extremely confusing to any one not intimately familiar with the the intricacies of nomenclature, and do not serve Wikipedia well.

So what to do with this article? Should it remain as now and be about Therapsida as a grade? Should it be re-named to preserve coverage, or re-written to reflect phylogenetic nomeclature as Smokeybjb suggested? Should we be open about using words like grades when that's what we do, or pay lip-service to the clade concept without actually reflecting it in the article coverage? Petter Bøckman (talk) 21:23, 28 November 2011 (UTC)

"The problem is that this selection is not at all representative of Therapsida as a clade." Then it needs to be fixed. This is similar to a discussion we recently had at Dinosaur. That article treats the subject as if it were the grade of non-avian dinosaurs, when no credible researcher has used the term that way in decades. This isn't a tacit implication that the article should be about the grade--it's an implication that the article is severely out of date and out of step with modern usage. There's also a more pernicious implication: that yes, due to phylogenetic nomeclature, there is less use for grand overview articles like Dinosaur. The exclusion of birds highlighted this, but the attempted re-wrirtes showed that the problems have always been present. There is veryy little to be said about "dinosaurs" (or "therapsids") as a whole other than listing their apomorphies and giving summaries of their included sub-groups. much, if not all, of the content at Dinosaur is not about dinosaurs in general but specific to one of their wildly diverse set of subgroups. If I told you an animal was a "dinosaur", this conveys so little information that it's practically useless. Same goes for therapsids. IMO more time should be spent focusing on major sub-group articles of each. MMartyniuk (talk) 13:51, 29 November 2011 (UTC)

Well, Benton uses "Dinosaur" in the older sense, and he is still publishes in prestigious journals, so I will contest your assertion that no credible researcher has used the term that way in decades. Granted, he is the odd man out, but it clearly shows that as long as you are mindful of how you word your work, your chosen classification is largely irrelevant as long as it communicate whet you wish it to. I have said as much in the Dinosaur-discussion: Careful wording will allow the two interpretations to live side by side.

Don't get me wrong Gents, I have no objection to an article on Therapsids (trad) + Mammalia (or Tetraceratops + Homo if you like), just like I have no objection to an article on Sauropsida. In fact, I have contributed quite a bit to the latter and amending the Tetrapod article to be about the whole group is high on my agenda. I do however find your view that there is "very little" to be said about grades like Dinosaurs of Therapsids quite peculiar. In fact, I think we must experience reality very differently if a group that so spectacularly dominated the fauna for more than a 100 million years is not interesting in itself. Good luck telling that to every new generation of kids growing up to realize their world was once populated by an entirely different cast of characters from that of their point-and-look toddler's books!

Granted, to the phylogenetic researcher, the traditional Dinosauria, Therapsida and Labyrinthodontia is of limited interest, but Wikipedia is not written for them. Phylogenetics is not the only valid palaeontology discipline, there's also palaeo-ecology, eco-physiology etc, and Wikipedia is for the layman, not for the experts. A simple counting of hits on the article Dinosaur will show that just this kind of large summary articles are very much in demand. Petter Bøckman (talk) 20:05, 29 November 2011 (UTC)

"I think we must experience reality very differently if a group that so spectacularly dominated the fauna for more than a 100 million years is not interesting in itself." I don't mean such groups aren't interesting, I just mean that, in an effort to avoid duplicating content, there isn't much to be said on a general overview page--all the good stuff goes on subpages. what can be said a about Dinosauria in general? Here's what I usually see: They walk on two legs or four (net information gained=0). They either eat meat or plants or both (net=0). They don't fly or swim except the ones that do. They have scaly skin except a lot don't. They lived everywhere (but only on the planet Earth!). Ok... that really took a lot of words to say absolutely nothing. Really, such overview pages tend to simply become glorified tables of contents for their subpages, and in that light there's no reason not to include ALL subpages (birds for dinosaurs, mammals for therapsids). MMartyniuk (talk) 20:43, 29 November 2011 (UTC)

Again, I think the shere number of hits on the Dinosaur article bears me out. Any statistics on how many hits on Dinosaur vs. e.g. Ornithischia? There's always room for improvement, but at least to my eyes the Dinosaur article is quite good and informative. Sure there's a lot of goodies in the lower pages, but that doens't make "Dinosaur" a bad article. It has a general overview, some history, some neat examples, nice pictures and lot's of relevant links. Is there a reason not to do the same for Therapsida?

Edit: I have re-read the lede, and yeah, it sucks. Part of the problem is trying to cram birds into everything. It clutters up the information the article is trying to convey.

With the danger of sounding pedantic, there's a reason general textbooks are divided into chapters like "Jawless fishes", "The advent of reptiles", "Years of the Dinosaurs" (Colbert and Morales, 1990) or "Primitive Mesozoic Mammals and Monotrems", "Aquatic Reptiles" and "The Conquest of Land and the Radiation of Amphibians" (Carroll, 1988). It's because it is a sensible way of diving up vertebrate palaeontology into reasonably logical topics. Both were written when phylogenetics became common and could have been arranged strictly phylogenticaly, but these two books are written to offer an introduction and give the student an overview. It may not be everyones mission on Wikipedia to do the same, but it certainly is mine. Seeing that the WP guidelines specifically mention secondary sources (i.e. textbooks), I think "general introduction and overview" is the right level to aim at. In this article, I think a general overview of the therapsid chapter of synapsid evolution would be appropriate. Both the books I mention actually have a chapters named "Therapsids", devoted to just that. Petter Bøckman (talk) 22:06, 29 November 2011 (UTC)

For the record, secondary sources are not limited to textbooks. Popular works and encyclopedias by primary researchers should count as well. I'd have no objection to modelling Therapsida on the current version of Dinosaur as long as it does not in any way explicitly exclude mammals. Leaving them out for now just makes it somewhat incomplete, not wrong. MMartyniuk (talk) 13:37, 30 November 2011 (UTC)

Like in the Dinosaur article mammals should be mentioned where appropriate, but there's no use in cramming mammals into every statement about physiology, build, groups etc. Just like the Dinosaur article has a summary section on the origin of birds, this one should have one on the origin of mammals. The idea is to make the phylogeny clear, without overdoing it. Petter Bøckman (talk) 14:23, 30 November 2011 (UTC)

Thecodonts

I see there's objection to use of the word Thecodont. I know thecodonts represent a grade (I know of no-one who ever argued otherwise), but the term is still used for "basal archosaurs", i.e. any archosaur that's neither dinosaur, pterosaur nor crocodylomoprph. The linked Wikipedia article explains it quite nicely.

In the lede, it is described how therapsids faced strong competition from "archosaurs and phytosaurs". Well, that's all fine and dandy, except there archosauria is a lot of thing, including birds, and it requires the reader have a very good grasp on stratigraphy to realize that "archosaurs" here is neither dinosaurs nor early crocodiles, but their "running crocs" ancestors, i.e. the "thecodonts". Using archosaur like it is now, is a bit like using tetrapod when discussing labyrinthodonts and expect the reader to understand when Tetrapoda is a clade and when it's just the basal members. Sometimes we need to refer to grades, and when they actually have a name we should use it. Petter Bøckman (talk) 20:01, 20 February 2012 (UTC)

" but the term is still used for "basal archosaurs"" By whom? I have never seen this term used by anyone outside children's books I had from the 1970s. I don't see what utility a term for "basal archosaurs" have since Archosauria is basally divided into two very well-known groups (Ornithodira and Crurotarsi). I do not see what the term Thecodont conveys in this context that Archosaur does not. If that's too broad, get specific: they faced competition from rauisuchids, early dinosaurs, aetosaurs, etc. I seriously doubt anyone would read this and think they were competing with birds, anymore than someone reading about early mammals would immediately think of humans.

"Sometimes we need to refer to grades, and when they actually have a name we should use it." I like to think I know more about the subject than you're average random reader, and I have no idea what basal archosaur groups the term "thecodont" is supposed to encompasses. Are we talking basal pseudosuchians here? Do lagerpetonids count? Aetosaurs? Anything that's not a dinosaur or a crown-crocodilian? Moreover, which source states they faced competition from thecodonts? It looks to me like that's the editor's personal use of the term in this context. MMartyniuk (talk) 20:49, 20 February 2012 (UTC)

"Early archosauromorph" would work fine, including everything that was once called a thecodont and more (prolacertiforms, rhynchosaurs, etc). I don't think most laypeople know what "archosaur" or "thecodont" means, so why not use what is more precise and more accurate? And although I see it used occasionally, the term "thecodont" is outdated. Smokeybjb (talk) 21:32, 20 February 2012 (UTC)

Hm, not sure where I saw the "competition" thing, but it might have been one of Benton's (again, I know) articles on faunal turover. I'll have a look. "early archosaur" is fine with me, but I think Dinoguy's right, we could be more specific. I'll see if i can find the reference. Petter Bøckman (talk) 21:47, 20 February 2012 (UTC)

Right now the lead doesn't mention competition, just replacement, which is good because therapsids may not have been out-competed as much as replaced by archosaurs (Benton's article here argues against competition). Smokeybjb (talk) 01:17, 21 February 2012 (UTC)

Thanks for the article link! It's a good one, but I know I've seen a newer one, with better figures though less of Benton's goofy animal drawings. I'll keep looking. I read the article, and from what I can see his conclusion seems to be that what finally relegated the therapsids to the back stage role at the end of the Triassic was the advent of conifer dominance. This seems reasonable, there's few modern mammals able to live on conifiers compared to other plant food. Petter Bøckman (talk) 13:31, 21 February 2012 (UTC)

As an aside, the Thecodont article mentions that someone has tried to give that group a phylogenetic definition. Anybody know what it was? If it included rauisuchians and phytosaurs, Thecodontia could in theory be resurrected for the Phytosauria + Archosauria clade, where it would have priority over Crurotarsi! MMartyniuk (talk) 14:21, 21 February 2012 (UTC)

Like the article says, Gardiner (1982)[1] uses Thecodontia as a clade, but then again he argued that mammals are the sister group of birds! There's more info about this in Gauthier et al. (1988).[2] I don't think Thecodontia will be resurrected any time soon. Smokeybjb (talk) 16:44, 21 February 2012 (UTC)

Sources for classification and clade?

This article needs more attribution in general, but the classification and phylogeny sections especially need sourcing, so that it is clear to the reader (and future editors) exactly how recent the data is and where it comes from. --Animalparty-- (talk) 00:33, 21 December 2013 (UTC)

Post-move

@Article editor: Hope you can update the infobox, navbox, categories, etc. because I'm not sure exactly what ramifications this move should have on them. Cheers, Jenks24 (talk) 10:43, 20 June 2015 (UTC)

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Adding a picture of a modern mammal to the species box.

I don't know if I should be asking this but since mammals are therapsids I think it would be a good idea if I added a picture of a modern mammal say a human to the species box.

@Quincy43425: If you think it's a good idea, then be bold and do it. —Trilletrollet [ Talk | Contribs ] 23:12, 16 May 2021 (UTC)

• Well, let me head off the impending disaster right now and say not a good idea. Because a) we have a very nice collage image at the moment, and unless the result would be a skillful extension of that collage, I don't think that would be an improvement; and b) frankly, Quincy43425 has so far shown debatable judgement and execution in their bold actions, and I and others have repeatedly advised them to seek input before making a mess... so I would suggest waiting for just that input here. --Elmidae (talk · contribs) 23:21, 16 May 2021 (UTC)

@Elmidae: Oh, ok. —Trilletrollet [ Talk | Contribs ] 23:37, 16 May 2021 (UTC)