Re: Deinosuchus and Tyrannosaurus

[Dinogeorge@aol.com]

In a message dated 97-06-22 10:15:01 EDT, dannj@alphalink.com.au (Dann
Pigdon) writes:

<< I have often
 wondered whether the concentration of scutes on the top could perhaps
 have originated due to predation from above - ie. from much larger
 predators such as dinosaurs. >>

Dorsal scutes are a primitive feature for practically all of Archosauria, and
crocs retain this feature presumably because it is useful to have the back
protected. It could well have arisen in early archosaurs for protection from
above from larger predators, such as therapsids. (Incidentally, therapsids
did not have dorsal scutes. Although I'm not terribly familiar with the
group, I can't recall any dorsally armored therapsids. This is probably why
they were able to evolve finbacks and such.)