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Re: Crocodile program on Discovery channel



>Jerry D. Harris writes:
>
>> Yes, crocs were around before
>> the dinos (although the eusuchians didn't pop up 'til what, the
>> Cretaceous), but in the sense of "what animal filled most of the global
>> niches of big terrestrial reptile after the dinosaurs?," crocs fit the bill
>> nicely.  (coupled, methinks, with big birds!)
>
>But the crocs _didn't_ fill most of the global niches.
>They are found only in and around rivers.  They certainly did
>not have anywhere near the range that the dinos did.
>In the Tertiary, mammals and birds filled more niches
>than crocs.
>
>-----------
>Achut Reddy                     So many fossils... so little time!
>achut@sun.com


Ouch! At least when you find a croc tooth in a deposit, you know who the
top predator was.

While it is true that crocs did not diversify as much as dinosaurs, birds
or mammals, do not understate the degree that they did diversify. Not only
have crocs held down a number of aquatic roles (principally the
broad-snouted ambush predator and the narrow-snouted piscivore) but there
have been fully adapted marine forms (possibly viviparous), a number of
terrestiral forms including the larger ziphodonts and the smaller
dog-crocs. We even have one croc over here that may have been arboreal.
What is more, a number of groups of crocs have independantly filled these
niches over the past 220 million years involving multiple convergencies.

What is more, crocs are the only living group that has a proven ability to
detect alcohol. Studies of human croc attacks in northern Australia show a
clear correltaion between human blood-alcohol content and the likelyhood of
being attacked by a croc. A similar correlation between decreasing human IQ
and croc attacks can also be demonstrated.

Viva la croc!

Cheers, Paul

pwillis@ozemail.com.au