Re: Hell Creek (long)

[John Bois <jbois@umd5.umd.edu>]

On Sun, 2 Jun 2002, David Marjanovic wrote:

> One thing is certain -- zalambdalestids are pretty distinct from every known
> Cenozoic mammal. They'd be pretty easily recognizable. For example, they
> retained epipubes, something no known Cenozoic eutherian has.

...and epipubes or something similar predisposed them to be susceptible 
to the bolide?

> Really, what could do it? Competition? Certainly not. Nest
> predation? Mosasaurs and plesiosaurs were viviparous.

One might fairly ask the corollary: why were these body plans targeted by
a bolide when the shark's body plan was not?

Do we know how big the neonate was in relation to the adult?  Did they go
on land to deliver (like seals)?  Perhaps a species of shark preyed them
to extinction

> ammonites _everywhere in the seas_ if not every last one had died at the
> K-T. Wouldn't we?

What is the status of synchroniety of land vs. sea extinctions?  Last I
heard this work had not been done.  It may be that they became extinct at
a slightly different time.  I'm sure you recognize that without a big
event there could be all sorts of reasons they went out.  Why were
ammonites targeted by the bolide in your view?