Gelatinous squid Posted April 17, 2009 Share Posted April 17, 2009 According to Wikipedia's article on the archosaurs, the birds and the crocs didn't diverge until the Archosauria order proper, but it seems to me that the Proterosuchidae were already well underway to becoming crocs, and the Euparkeriidae well underway to becoming dinos, long before the archosauria order branched off. So when did it start? Link to comment Share on other sites More sharing options...
mommabetts Posted April 18, 2009 Share Posted April 18, 2009 I bet our resident bird man can help with this one. Welcome to the forum. Link to comment Share on other sites More sharing options...
Auspex Posted April 18, 2009 Share Posted April 18, 2009 The Proterosuchia, being the most primitive of the Thecodonts, radiated explosively in the early Triassic with a confusing array of divergent and convergent evolution. The foundations for crocodiles, ornithischians, sauropods, and theropods were all laid at that time. Exactly where the direct ancestors of birds budded off is in dispute, but there is a consensus that it was after the crocodilians went their way. It is my opinion that Ornithurines share a common (non-avian) ancestor with the Enantiorthinines, but that the former are not derived from the latter. My thinking is that, in a cladistic view, "birds" evolved twice; phylogenically, it is a re-expression of genetic propensity. "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
Gelatinous squid Posted April 18, 2009 Author Share Posted April 18, 2009 Thank you for you welcome and for your response to my question. I hope you don't mind if I ask a whole lot more of them, but I have a lot rolling around in my head. Could I ask, would Euparkeria therefore be considered a good enough candidate for the latest common ancestor between crocs and birds? Link to comment Share on other sites More sharing options...
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