RE: The Croc That Wanted to Be a Dinosaur

[Tim Williams <twilliams_alpha@hotmail.com>]

Jay <sappororaptor@yahoo.com> wrote:

> Except that Chatterjee had already named Shuvosauridae in 1993.

Thanks for the correction - I'd forgotten about that one.

Jeff Hecht wrote:

> What I find fascinating is that the suchians and the true dinosaurs evolved 
> in parallel with similar traits through the Triassic, much as the two lines 
> of birds did in the Cretaceous, looking quite similar except for bones in 
> the ankles and legs that distinguished them. There also are parallels in 
> extinction patterns. The end-Triassic extinctions wiped out the 
> dinosaur-like crocs; the end-
> Cretaceous extinction wiped out the enantiornithes.

The non-crocodylomorph suchians certainly bit the dust at the end of the 
Triassic.  Some rather theropod-like crocs (as in 'crocodylomorphs') 
persisted into the Middle Jurassic (like _Junggarsuchus_) and even the Late 
Jurassic (_Hallopus_/_Macelognathus_).  These 'sphenosuchians' were rather 
small, gracile, and cursorial, with an erect dinosaur-like posture.

The poor Suchia were whittled away throughout the Mesozoic and Cenozoic, 
with the various suchian groups disappearing over a very long period of 
time: basal suchians (shuvosaurs, aetosaurs, etc), 'sphenosuchians', 
protosuchians, thatalattosuchians, dyrosaurs, sebecosuchians... until only 
one lineage was left: the crown-group crocodylians.

Cheers

Tim