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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 |
1401 South IN 421 |
Westville, IN 46391 |
(219) 785-5251 (office) |
(219) 785-5355 (Fax) |
rhengst@centaur.cc.purduenc.edu |
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