RE: Turtles and Crocodylians are not Reptiles - no? What are they?

[Nick Pharris <npharris@umich.edu>]

Quoting Tim Williams <twilliams_alpha@hotmail.com>:

> > Closer to hippos thant to mesonychids anyway.
>
> Actually, no.  Under Thewissen &c's phylogeny, there is a 3-way  
> polytomy (trichotomy) composed of Mesonychia, _Andrewsarchus_ and  
> the Cetacea+Artiodactyla clade.  The hippopotamids are inside the  
> crown Artiodactyla, in the Suina clade.  Because the whales are  
> recovered in a Cetacea-Raoellidae clade at the base of the  
> Artiodactyla, cetaceans are *not* closer to hippos than to  
> mesonychians.  Not according to this phylogeny, anyway.

Yes they are.  The existence of a "Cetacea+Artiodactyla clade" that  
excludes Mesonychia means that cetaceans are closer to hippos (as  
artiodactyls) than they are to mesonychians.  It's just that, under  
Thewissen et al.'s phylogeny, cetaceans are not any closer to hippos  
than they are to llamas, babirusas, chevrotains, mule deer, okapis,  
etc., etc.

--Nick Pharris