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Re: Crocodile program on Discovery channel



> AAAARRRGH!
>       The believe that crocs have changed little since  first appearing 
> in the late Triassic over 225 mya (_around_ the same time as the earliest 
> dinosaurs :o)) is a common one.  Living crocodylians (alligators, 
> crocodiles, and gavials), while confirming to the standard eusuchian base 
> plan, give no hint of the vast range of diversity of those now extinct.  
> Indeed, the niche-filling capabilities of crocs should not be 
> underestimated. Early crocodylomorphs such as sphenosuchians and 
> protosuchians appear to have been gracile, quick-moving terrestrial 
> predators.  It wasn't until the Middle Jurassic that crocodylomorphs 
> adopted the amphibious mode of life they came to dominate so successfully.
> However, these taxa, known as mesoeucrocodylians, in addition to the 
> classic amphibious ambush predator, filled many roles. Thallatosuchians 
> successfully adapted to marine life, evolving flippers and a heterocercal 
> tail. Hsisosuchians and sebecids seem to have been terrestrial, evolving 
> laterally compressed snouts and trechant, serrate teeth like those of 
> carnivorous dinosaurs - traits also found in several eusuchian taxa which 
> may also have been terrestrial (for example, pristichampsines and 
> mekosuchins).  The relatively short-snouted notosuchids may also have 
> been terrestrial.  The blunt, intricately fluted teeth of uruguaysuchians 
> and some notosuchids were very similar to those of herbiverous dinosaurs 
> and lizards, suggesting these animals may also have been herbiverous.  
>       It's just a shame things like this aren't around today :o(
> 
> Cheers,
> 
> Steve Salisbury
> Vertebrate Palaeontology Laboratory
> School of Biological Sciences
> University of NSW
> Australia
> P2158753@vmsuser.acsu.unsw.EDU.AU

Does anyone know where fossil skeletons (postcranial - thoracic vertebrae 
preferred) of some of these crocodilian ancestors could be viewed?  At least in 
North America???  I am interested in the evolution of breathing in Dinos (a 
major key to activity limits) and have found an interesting progression from 
Triassic --> Jurassic/Cretaceous that occurs in one form or other dinos ... 
Ornithischians and Saurischians alike.  However, I really need to look at the 
earlier forms of archosaurs to get a feel for what precursor groups are doing in
the Triassic.  Dinos didn't just live in isolation the way they do in movies.

Rich


______________________________________________________________________________
Rich Hengst                       |   
Biol. Sci. @ PUNC                 |
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rhengst@centaur.cc.purduenc.edu   |
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