Talk:Saurischia

Considering that Dinosauria is part of the class Archosauria, shouldn't Saurischia be part of this same class instead of Reptilia? DarthVader 09:54, 17 July 2005 (UTC)

Agreed, Class Archosauria seems to be standard across the dinosaur entries. Fixing this and the mis-spell of Aves as "Avis" in the taxobox. Dinoguy2 02:33, 9 December 2005 (UTC)

Visible

Is it possible to see the different types of hips reflected in external form or stance?

The main visible difference in life would have been the size of the "gut"--the back-pointing pubis of ornithischians (and also herbivorous theropods) allowed for a longer digestive track and a longer belly. The more anterior center of gravity created by this may be why so many ornithischians were quadrupeds.Dinoguy2 23:38, 12 September 2006 (UTC)

In reply to the comments about classification above, Archosauria is NOT a class. It is a subclass of Reptilia. Archosaurians were most definitely reptiles, diapsids specifically. See the website of the University of California Museum of Paleontology here: http://www.ucmp.berkeley.edu/taxa/verts/archosaurs/archosauria.php

You will see a discussion of Archosauria as a subclass of Reptilia in the most authoritative general work on dinosaurs, The Dinosauria by David B. Weishampel and Halszka Osmólska. See also this abstract from the study Phylogenetic taxonomy and the major archosaurian (Reptilia) clades The abstract may be seen here: http://www.mendeley.com/research/phylogenetic-taxonomy-major-archosaurian-reptilia-clades-13/.

Dinosaurs were reptiles. I'm not sure why there is any doubt about this. — Preceding unsigned comment added by 50.113.28.134 (talk) 02:00, 7 December 2011 (UTC)

Rank?

Why is Saurischia an unranked clade rather than an order in the taxobox? Petter Bøckman (talk) 16:22, 5 May 2012 (UTC)

Because most paleontologists working in this area no longer rank it as an order. You reverted the change to clade in the taxobox saying that an "absolute majority of relevant sources" use order. Where is this demonstrated? It is no where in the article text and not backed up by reliable sources. I can't recall the last time I saw Saurischia referred to as an "order" in any source other than Benton 2004, and I read a lot of sources on this topic ;) A Google Scholar search for the past 10 years for "order saurischia" returns 74 sources, while "saurischia" alone returns over 1400. It does not look to me like a majority of modern sources rank this clade as an order. If I'm mistaken please include relevant sources in the text and then change the taxobox to follow. MMartyniuk (talk) 17:10, 6 May 2012 (UTC)

I thnik we have been over this before, but I guess this is a secondary versus primary sources problem. We're supposed to follow textbooks like Benton rather than primary articles for such things. Petter Bøckman (talk) 17:28, 6 May 2012 (UTC)

I have many current, popular books (also secondary sources) that refer to Saurischia as a clade. Why are textbooks the favored secondary source? IMO we should use sources that best reflect the state of the art. There is very little of Benton's dinosaur classification that's currently up to date, and some of it flies in the face of all other sources (like avian oviraptorosaurs). MMartyniuk (talk) 15:36, 7 May 2012 (UTC)

I disagree that this is a primary/secondary problem. A source in the primary literature for a piece of information isn't necessarily a primary source. This is especially true for facts like "saurischia is an unranked clade", which would have been referenced and discussed over and over again. For all we know any given article mentioning that fact is ten degrees of separation its original primary source n the primary literature. Abyssal (talk) 16:20, 7 May 2012 (UTC)

Not to mention that in a science like paleontology, unlike say history, a journal article isn't a primary source--the fossils it describes are the primary sources. That's why it's OR to write personal observations about published photographs but not to report the findings of the studies of those bones. If we had to use textbooks alone as sources, a vast majority of dino articles should not exist. Most species are never mentioned in your average textbook. Benton's classification doesn't even include any taxa between Family and Infracohortlegion, let aloone genera that do not fall under any particular family. MMartyniuk (talk) 16:50, 7 May 2012 (UTC)

Fossils are the primary source? Are you pulling my leg here, or are you really arguing that dinosaur study is somehow fundamentally different from all other branches of science? According to Wikipedia policy, [papers are the primary sources]. As to you question why, the reason seems to me at least to be that the typical overview textbook is written by an expert with years of experience in the field, and presents a well rounded picture of the knowledge. Whatever makes it into such a textbook is likely to be well tested and well known. While the criterion for inclusion in Wikipedia is verifiability, it would be nice if the facts are true too, and secondary facts are better checked than primary ones.

Having said that, I have no problem with primary sources for facts that are questionable or not covered in the secondary literature, as in the example you cite above (avian oviraptorosaurs). With the knowledge of dinosaur phylogeny is in constant flux these days (we live in the dinosaur renaissance apparently), primary sources obviously have their place, but we need to show due caution when using them. Someone calling Saurischia a clade does not mean it also can't be an order. I've written research papers myself (some small stuff in an entirely unrelated field), and I don't use the formal family and genus other than in the rare occasions when I need to list a formal classification (i.e. next to never, I'm an ecologist). Perhaps the next generation of entry level university textbooks on dinosaurs will be written without any formal ranking at all, but we'll have to wait for someone to write the next "Vertebrate palaentology" to find out. Petter Bøckman (talk) 10:58, 8 May 2012 (UTC)

"we'll have to wait for someone to write the next "Vertebrate palaentology" to find out." Again, why this book in particular? There are numerous non-textbook secondary sources, also written by experts with years in the field (like Tom Holtz's popular audience books) which explicitly reject ranked nomenclature already. Benton is rather infamous as being one of the last holdouts of ranks within vert. paleontology. This is somewhat analogous to saying that since many secondary sources on Mesozoic birds are written by Alan Feduccia and Larry Martin, we should adopt a bird-are-not-dinosaurs position until they decide to "update" their texts with the "new fact" that birds are in fact dinosaurs. Never gonna happen. MMartyniuk (talk) 13:35, 8 May 2012 (UTC)

It doesn't need to be this book in particular at all :-) As you may remember from some of our conversations, I'm not overly enamoured by Benton's classification either. I could have suggested any title along the same lines (Vertebrate Paleontology and Evolution - Carroll, Evolution of the Vertebrates - Colbert, to mention two), it's just that books on this topic tend to be named "Vertebrate palaentology" (Benton, Romer, Russell, Schoch). I was trying to put through the point that the basic overview book of this type is just the type of source that is ideal for general Wikipedia articles. These books seem to have a lifespan of perhaps 30 years (Romer's were in print for about 40, over 50 if you include "The Vertebrate Body"), so it is a bit early to call.

There's a fundamental difference between this argument and Feduccias stance on birds. Feduccia & Martin makes statements on objective facts (phylogeny) which can be tested scientifically. Whether using ranks is right or wrong is not a scientific question, it is one of philosophy, tradition and practicality.

Reguarding Holtz's books, I think we again may see a bit of cultural difference here. As I have said earlier, rankless numenclature seems to have their strongest following in the US, France and Germany, less so in Britain and the rest of Europe. This is why I argue for a "live and let live" approach, English Wikipedia is the de facto main Wikipedia, and caters to more than the an US audience. Petter Bøckman (talk) 13:31, 9 May 2012 (UTC)

"I was trying to put through the point that the basic overview book of this type is just the type of source that is ideal for general Wikipedia articles."I don't disagree in principle. The questions are, do all of these various books include ranked classifications? If so, do they all agree on the ranks? If not, what is the majority usage? All the various schemes can and should be discussed in the text. But for the taxobox, we need to follow consensus where it exists. Right now there are zero sources regarding modern use of ranks for Saurischia discussed and cited in the text. All the sources besides Benton I personally have access to, popular and technical, treat this taxon as unranked. If you have more popular sources/textbooks that rank it, by all means add the cites and change the taxobox. But it needs to be verifiable, not "well, everybody knows it's an Order, and Benton calls it that, so good enough". If other sources rank it, we need to add them to the classification section, determine if they're the majority, and determine if they agree on the rank. If only Benton is calling this thing an Order during the last decade, he;s a fringe minority and should be ignored. MMartyniuk (talk) 13:54, 9 May 2012 (UTC)

I haven't seen those by Russell, Schoch (both whom appear to be article collections rather than textbooks), but all the other books I mentioned have Saurischia as an order. I can have a look at others if you want me to. Afters Seeley ranked Saurischia and Ornithischia as orders in 1888, they have generally kept that rank, even among the "Dinosaurs are a class!"-people. I haven never seen it ranked otherwise, hence my surprise at Saurischia as an unranked clade. Benton has his unusual ideas (I think Synapsida as a class is his invention), but he's very much a traditionalist, and there's no compelling reason for changing the rank of a well defined and well understood unit like Saurischia. While since 1888 is hardly "always", it is a very long time of taxonomic stability. Petter Bøckman (talk) 15:47, 9 May 2012 (UTC)

I don't doubt most people traditionally rank it as an order, but I'm wondering if the majority of textbooks rank it at all. By the way, in Spencer Lucas' Dinosaurs: The Textbook, I see he ranks all the traditional "suborders" as orders, so Saurischia is presumably a higher rank. Greg Paul and Bob Bakker have also given various different taxa the Order rank (justifiably IMO, as the primary de facto divisions of dinosaurs aren't Saurischians & Ornithischians but Theropods, Sauropodomorphs and Ornithischians). MMartyniuk (talk) 17:37, 9 May 2012 (UTC)

Yeah, if they were to find it is a three way split (or even with Bakker's old "Dinosaur heresies" with an Theropoda-Ornitischia clade), that would be reason to change the ranking. If it were all up to me, I'd go with three orders, but I'm not the ICZN. Seems I need to check out Spencer Lukas. Isn't the monophyly of Saurischia fairly certain? I'm not a dinosaur guy per se, so I haven't followed the literature closely. Petter Bøckman (talk) 19:41, 9 May 2012 (UTC)

The monophyly is certain, the division is more a reflection of the "major groups". Sauropods branched off one node closer to theropods than ornithischians, but nobody ever really talks about "saurischians" in general because sauropods and theropods ended up diverging so much. If by "oder" we mean a major body plan within a larger group, it doesn't make much sense to put Apatosaurus and Tyrannosaurus in the same "order" to the exclusion of Edmontosaurus. The only real commonality are hip arrangement (also shared with very primitive ornithischians) and air sacs. (and the ICZN doesn't govern anything above family, which is why everybody has their own scheme ;) ). MMartyniuk (talk) 20:55, 9 May 2012 (UTC)

My impression is that one of the advantages Wikipedia has over other encyclopedic venues is that it can react quicker than the latter to changes in various fields. While that may lead to some fickleness, I do feel that it's a characteristic to maintain and even strive for. Also the prevalence of typological thinking vs tree-thinking in the rest of Europe... well at least in Portugal, is more due to the inertia of the educational system (unchanging requirements? lack of time to update syllabi?) than anything else. For instance, a more recent (3 years) syllabus for Botany at the University of Algarve does include a moderately up to date cladistic classification of plants, though some 5 years earlier I was still hearing about protozoans as animals. As such I'd rather that Wikipedia reflected next-to-current usage by scientists in the pertinent fields. Dracontes (talk) 10:02, 10 May 2012 (UTC)

You are right in seeing this as a larger question, Dracontes. My personal motivation is to try to preserve what is best from both traditions, they each have their good and weak sides. Petter Bøckman (talk) 13:44, 10 May 2012 (UTC)

Birds evolved from ornitischians?

An editor have now twice put in an edit stating that birds evolved from "bird-hipped" Ornitischians. This is not correct. The term ornitischia is a reference to the other order of dinosaurs, the order that birds did not evolve from. While a similarly structured hip-bone evolved separately in the theropod family Therizinosauridae, does not make them in any way ornitischians, they are still saurischians. The typical hip-bone found in modern birds actually evolved after the early birds had evolved from maniraptoran ancestors. The whole (grade) Maniraptora had straight up lizard-like hips, and so did Archaeopteryx. So even if the terms Saurischia and Ornitischia are used as anatomical terms rather than systematic (which they never are btw), the edits that birds evolved from ornitischian dinosaurs are wrong. Petter Bøckman (talk) 05:53, 20 May 2012 (UTC)

Duh, you don't get it don't you? I'm not saying that at all! The way the text is written makes it appear as bird hips evolved separately from Saurischian hips! But this is not true. They ARE Saurischians who evolved a hip-structure similar to Ornithischians as a form of convergent Evolution! — Preceding unsigned comment added by 80.187.110.13 (talk) 11:05, 20 May 2012 (UTC)

This is a case of confusing grammar in the article. "evolved independently from" didn't mean "independent origin than" but "from among" saurischians. I edited the paragraph to clarify things. MMartyniuk (talk) 19:13, 20 May 2012 (UTC)

Much better now. Thanks. — Preceding unsigned comment added by 80.187.110.110 (talk) 21:26, 20 May 2012 (UTC)

AH, good! Only I suppose it should be "evolved trice", we must not forget the therizinosaurs. Petter Bøckman (talk) 06:29, 21 May 2012 (UTC)

Why removed theropoda?

@4444hhhh: Why did you remove the Theropoda with this edit: [1]? --Jules (Mrjulesd) 21:50, 22 March 2017 (UTC)

I'm guessing it's because a recent paper showed that Theropodas were more closely related to Ornithischians than to Sauropods, which from a cladistic standpoint makes sense (feathers are found in both theropods and primitive ornithischians, but not in sauropods or primitive saurischians). Of course other scientists are reviewing the paper and so it might take time for it to officially change, but the overall view of the paper are positive as it solves many of the problems with the current classifications. --2602:306:3160:6420:8D30:2EBE:15E1:45BA (talk) 16:10, 31 March 2017 (UTC)

There is no such thing as an "official" change, what matters is how widely the idea is accepted in the literature. And we have no idea yet, since there have been no published reactions to it. In any case, Theropoda can't be removed from here before there is scientific consensus, and that is unlikely to happen any time soon, so we should just present the different hypotheses. FunkMonk (talk) 16:13, 31 March 2017 (UTC)

Aren't crocodiles saurischians, too?

At the end of the Cretaceous Period, all saurischians except the birds became extinct in the course of the Cretaceous–Paleogene extinction event.

What about the crocodiles? They are also still around.--2003:CE:BF18:60BF:310A:2384:DFE0:58EB (talk) 13:08, 15 March 2020 (UTC)

Crocodilians are not neither saurischians nor dinosaurs. See Archosaur#Phylogeny.Kiwi Rex (talk) 14:05, 19 June 2020 (UTC)