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Re: Tyrant stuff (no longer ranting) (was RE: Rant (was RE: Details on SVP 20...
From: "Andrew A. Farke" <firstname.lastname@example.org>
Subject: Re: Tyrant stuff (no longer ranting) (was RE: Rant (was RE:
Details on SVP 20...
Date: Sat, 9 Nov 2002 13:39:15 -0700
> If it was so easy to get across, why are there no ceratopine or
> centrosaurine ceratopians in Asia (for example)? Easy for one means easy
I'm undecided on the on-list land bridge discussion, but I will throw in
point that just because a land bridge exists doesn't mean that a species
will necessarily utilize it. If a species does utilize it, this doesn't
that it will become firmly established (and hence fossilized). Habitat
differences between the two continents may have rendered it difficult for
ceratopsids to become established in Asia
This is the best explanation IMHO. Note that taxa which successfully
emigrated were broad snouted e.g. ankylosaurids, hadrosaurs, whereas narrow
snouted, more selective feeders such as nodosaurs and big ceratopsids may
not have found enough of their preferred vegetation to survive in Asia,
where the climate was generally more arid.
(or at least the areas of Asia for
which we have fossiliferous strata). I make this statement with the caveat
that it's pure speculation. The fossil record for Asia *is* pretty patchy.
It is true that known LK Asian environments were well inland but some
ceratopsids lived in intermontane basins e.g. Torosaurus, so their absence
in Asia seems real.
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