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Re: Cretaceous taeniodont
On Fri, 9 Apr 2004, Phil Bigelow wrote:
> I have often wondered why there are no unambiguous examples of fossorial
> non-avian dinosaurs.
Body plan. Dinosaurs were primitively bipedal. Presumably, this was part
of the package that contributed to their early success. I was just
re-reading Orwell's brilliant essay on mining. Two-legged
transport in the confines of tunnels is a nightmare. This could be part
of the reason, at least. Many large dinsoaurs were secondarily on four.
The fact that no small dinosaurs did this (so far) _may_ indicate that
others had the edge here.
> This doesn't appear to be a matter of competition for a niche. Consider
> that mammals and lizards both inhabit and exploit the subterranean world,
> and both have done so since at least the mid Mesozoic.
Lizards and mammals may share the same habitat; they are _not_ niche
competitors. Potential differences: forage at different times, tolerate
different heat regimes, etc., etc.