Comments on: Poposaurus, Postosuchus, and the Dinosaur Mimic Croc Walk http://phenomena.nationalgeographic.com/2013/02/21/poposaurus-postosuchus-and-the-dinosaur-mimic-croc-walk/ A science salon hosted by National Geographic Magazine Mon, 20 May 2013 20:41:54 +0000 hourly 1 http://wordpress.org/?v=3.5.2-alpha By: David Peters http://phenomena.nationalgeographic.com/2013/02/21/poposaurus-postosuchus-and-the-dinosaur-mimic-croc-walk/#comment-41513 David Peters Fri, 01 Mar 2013 11:57:39 +0000 http://phenomena.nationalgeographic.com/?p=151584#comment-41513 What is it about Poposaurus and poposaurids that make paleontologists think they were croc relatives? The calcaneal tuber? The large reptile tree at reptile evolution.com recovers poposaurids as phytodinosaurs with a convergent development of a calcaneal tuber, the only dinosaurs to do so. This is convergent with crocs themselves, which also developed a calcaneal tuber after basal crocs, like Gracilisuchus and Scleromochlus, did not have one. One trait, even an ankle trait, does not trump the suite. It’s time to add more pertinent taxa and rerun the analysis.

]]> By: Cai Yuan http://phenomena.nationalgeographic.com/2013/02/21/poposaurus-postosuchus-and-the-dinosaur-mimic-croc-walk/#comment-41408 Cai Yuan Thu, 28 Feb 2013 11:25:26 +0000 http://phenomena.nationalgeographic.com/?p=151584#comment-41408 “Rauisuchidae” in scare-quotes is justified by its probable inclusion of Teratosaurus, however, giving Teratosauridae Cope 1871 priority.

]]> By: Fuzzy Logic http://phenomena.nationalgeographic.com/2013/02/21/poposaurus-postosuchus-and-the-dinosaur-mimic-croc-walk/#comment-41199 Fuzzy Logic Mon, 25 Feb 2013 12:18:48 +0000 http://phenomena.nationalgeographic.com/?p=151584#comment-41199 I believe that even though life on earth in this day and age is very refined, back in the prehistoric times is where i’d like to be. The lush trees, the inviting forest. Creatures of exceptional ability such as this. It makes you wonder what could have been, dosen’t it?

]]> By: jenny http://phenomena.nationalgeographic.com/2013/02/21/poposaurus-postosuchus-and-the-dinosaur-mimic-croc-walk/#comment-41195 jenny Mon, 25 Feb 2013 10:20:05 +0000 http://phenomena.nationalgeographic.com/?p=151584#comment-41195 oh my god they are graet and cool

]]> By: DWalker http://phenomena.nationalgeographic.com/2013/02/21/poposaurus-postosuchus-and-the-dinosaur-mimic-croc-walk/#comment-41103 DWalker Fri, 22 Feb 2013 20:35:58 +0000 http://phenomena.nationalgeographic.com/?p=151584#comment-41103 Imagine the first prehistoric findings…they all seemed weird and several nary seemed possible. Impressive data shows that biped creatures were not only a possibility but a reality. Weinbaum is brilliant.

]]> By: Brian Switek http://phenomena.nationalgeographic.com/2013/02/21/poposaurus-postosuchus-and-the-dinosaur-mimic-croc-walk/#comment-41097 Brian Switek Fri, 22 Feb 2013 17:23:48 +0000 http://phenomena.nationalgeographic.com/?p=151584#comment-41097 Got it! Thanks, 220!

]]> By: 220mya http://phenomena.nationalgeographic.com/2013/02/21/poposaurus-postosuchus-and-the-dinosaur-mimic-croc-walk/#comment-41095 220mya Fri, 22 Feb 2013 17:22:00 +0000 http://phenomena.nationalgeographic.com/?p=151584#comment-41095 Although in the past “Rauisuchia” and Rauisuchidae have sometimes been used synonymously, Nesbitt (2011) provided a formal phylogenetic definition for Rauisuchidae: The most inclusive clade containing Rauisuchus tiradentes (Huene, 1942) but not Aetosaurus ferratus Fraas, 1877, Prestosuchus chiniquensis Huene, 1942, Poposaurus gracilis Mehl, 1915, or Crocodylus niloticus Laurenti, 1768 (sensu Sereno, 2005).

Thus, by definition Rauisuchidae is monophyletic, and recent phylogenetic analyses suggest it includes Rauisuchus, Polonosuchus, and Postosuchus spp.

]]> By: Brian Switek http://phenomena.nationalgeographic.com/2013/02/21/poposaurus-postosuchus-and-the-dinosaur-mimic-croc-walk/#comment-41066 Brian Switek Fri, 22 Feb 2013 04:32:10 +0000 http://phenomena.nationalgeographic.com/?p=151584#comment-41066 Thanks, Randy. Although I’ve seen rauisuchid in quotes, as in Weinbaum’s paper. The varying usage is sometimes a bit confusing.

]]> By: 220mya http://phenomena.nationalgeographic.com/2013/02/21/poposaurus-postosuchus-and-the-dinosaur-mimic-croc-walk/#comment-41064 220mya Fri, 22 Feb 2013 04:05:04 +0000 http://phenomena.nationalgeographic.com/?p=151584#comment-41064 Brian – there’s no need to use Rauisuchidae or rauisuchid in quotes – that is a monophyletic group. There terms that require quotes are “Rauisuchia” and “rauisuchian”.

]]> By: BJ Nicholls http://phenomena.nationalgeographic.com/2013/02/21/poposaurus-postosuchus-and-the-dinosaur-mimic-croc-walk/#comment-41048 BJ Nicholls Thu, 21 Feb 2013 23:42:23 +0000 http://phenomena.nationalgeographic.com/?p=151584#comment-41048 Rany Irmis’ recent UFOP talk had a great takeaway lesson. Modern crocodilians are not representative of their Triassic forebears, and there are recent fossils that show that crocodylomorphs were even more diverse earlier than previously understood.

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