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Re: If the asteroid had missed...




On Wednesday, March 14, 2007, at 08:33 AM, jbois@verizon.net wrote:

Dinosaurs are still here...they are just no longer competitive in the large animal niche. Predatory tactics of birds, mammals, and reptiles are probably prohibitive for any animal whose nest is dependent upon defending a nest in the open field (crocs having the advantage of ambushing a nest predator _and_ seeing very well at night...a luxury probably not afforded most dinosaurs).

Ah, but here's the rub: even if you are correct, the modern faunal composition probably wouldn't exist without the bolide effects, which creates a bit of a Catch 22. Of course, we've debated this point before and I know we're in relatively stark disagreement about possible causal factors for higher-clade level, global extinction events, as well as the relative importance of viviparity in mammals.


Cheers,

--Mike H.


Michael Habib, M.S. PhD. Candidate Center for Functional Anatomy and Evolution Johns Hopkins School of Medicine 1830 E. Monument Street Baltimore, MD 21205 (443) 280 0181 habib@jhmi.edu