Re: Fossil Dinosaur Eggs Discovered

["John V Jackson" <jjackson@interalpha.co.uk>]

--Original Message-- From: Thomas R. Holtz, Jr. <th81@umail.umd.edu> 19
November 1998 13:43



>At 07:59 PM 11/18/98 -0000, John Jackson wrote:
>>Are these skin impressions from the first ever scaly small endotherms, or
>>are they "feather buds"?
>>
>
>The skin impressions appear very similar to those of adult sauropods.
>
>We now have data to show sauropods lacked feathers/proto-feathers/whatever
>prior to hatching, and as adults.  Until such time as we find positive
>evidence feathery juvenile sauropods, we should work under the assumption
>that they weren't feathered at any part of their life cycle.
>
>This is the data end.  What this implies about the thermal ecology of baby
>sauropods is another question entirely.


Mmm.  A surprisingly interesting discovery.  I hadn't expected feathers but
I had expected fur.

Well, just because we don't have multi-ton land carnivores today doesn't
necessarily mean they are impossible, and in the same way, maybe not having
insulation might not be a bar to some kind of endothermy.

So now fur could have started anywhere up to, say the mid Jurassic (giving
_Sinosauropteryx_ time to get going) and after the split between the
sauropodomorphs and the theropods.

Or, sauropodomorphs could have lost it.