Re: paleonet Czerkas and Norell in Discover

[Dinogeorge@xxxxxxx]

In a message dated 7/26/2005 1:44:16 PM Pacific Standard Time, tijawi@yahoo.com writes:

Theropods also have furculae, so this does not advance your argument one iota.  All this demonstrates is that furculae are primitive for the Saurischia.  The evidence putting segnosaurs in the Theropoda is overwhelming.

What prompted me to exclude segnosaurs from being derived prosauropods was that they would have had to evolve a furcula independently. Furculae plus other maniraptoran features together would have "overwhelmed" the hypothesis of prosauropod ancestry for segnosaurs. But now that we have furculae in prosauropods, too, we're practically back to square one. Segnosaur forelimbs alone, without considering the furculae, are significantly different from those of other maniraptorans and suggest convergence as a possibility rather than common descent. Eshanosaurus is transitional in both time and morphology between prosauropods and segnosaurs; too bad there's not more of it. Once the errors in the description of the skull of Erlikosaurus are corrected, the skull becomes quite prosauropod-like as well.

 

The evidence for putting segnosaurs into Theropoda is not overwhelming, it's merely equivocal.