PRISTICHAMPSIDS etc

[darren.naish@port.ac.uk]

On various crocodyliforms, Tracy wrote...

>I am aware of the baurusuchids and notosuchids(Is this correct?) Did
>the Baursuchids secondarily become carnivores from an ancestral
>herbivorous state?

If Sebecosuchia is a clade (a few MPTs of some authors find that 
sebecids and baurusuchids to be monophyletic) then, no, there is no 
reason to think that baurusuchids descend from non-carnivorous 
ancestors. It is interesting that some studies find a notosuchian + 
sebecosuchian clade however (this has been called Ziphosuchia). At 
least some notosuchians were possibly herbivorous.

Chris wrote...

> Within Crocodylia (strict sense), pristichampsines and one 
> mekosuchine lineage (Quinkana) are thought to have been primarily 
> terrestrial.

Incidentally, Rossman has also argued that _Quinkana_ is not a 
mekosuchin but a pristichampsid (I'm following Willis there in having 
mekosuchins as a subfamily-level group of crocodylines and following 
Rossman in regarding pristichampsids as a family-level taxon).

Tracy - there is a lot of discussion of pristichampsid/quinkinine life 
habits in papers by Molnar, Langston, Rossman and others. A frequent 
suggestion is that these animals were something like large living 
varanids. It has also been argued, however, that these crocs were not 
necessarily fully terrestrial but might have ambushed prey from the 
water.

"His predatory dinosaur _Irritator_ got its name because it was 
obviously irritating to other creatures" - - Naish 2000 (and an editor)

DARREN NAISH 
PALAEOBIOLOGY RESEARCH GROUP
School of Earth, Environmental & Physical Sciences
UNIVERSITY OF PORTSMOUTH
Burnaby Building
Burnaby Road                           email: darren.naish@port.ac.uk
Portsmouth UK                          tel: 01703 446718
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