Re: Mammal diversity takes a 20 milion year step backwards!

[TwoSpooky <bg50001@ltec.net>]

John Bois posted on 6-2-96:

> Finally, I am tempted to speculate that all the pieces were in
>place for a multi-species onslaught on the one thing all the
>dinosaurs had in common and COULD NOT CHANGE: they laid eggs and
>could not hide them!

        Why assume the eggs could not be hidden? The size of the
adults alone is not enough to speculate that they could never be
hidden. What about camoflage?

 Do we know that all dinosaurs were parentally invested?  Many species
of animal today lay thier eggs and leave them. There are even a few
types of bird that will place thier eggs in another bird's nest,
relieving them of any parental responsibility.

> Plain mammals _always_ herd!

        Ok, I'm being nitpicky....not ALL plains mammals herd. :)


>It still has stationary eggs and relatively defenseless hatchlings.
>Mammal carnivores could dig burrows and move their offspring--they
>were stealthy reproducers--dinosaurs could do neither.  Altricial
>mammal babies could cling to mummy's fur, or mummy could move baby
>by the scruff of its neck.  A dinosaur trying this tactic would have
>scrambled babies.

        If Dinosaur hatchlings were precocial, as the evidence
suggests, then the only problem they had was thier size. Baby
alligators, cats, etc.  are born with some defensive
capabilities. Also, it is common for young to have different
coloration than the parents to better hide and camoflage them.

        I am not so sure the Dinosaurs could not have moved thier
young without scrunching (or scrambling) them. I have seen rats, mice,
dogs, bears, and even crocodilians move thier young with no
damage. None of these animals used the scruff of the neck, the babies
were just picked up at the mid-section and moved.

ZooWoman