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(fwd) Re: Mammals as a cause of Dinosaur extinction



On 17 Dec 1997 20:34:38 -0500,  "Stan Engel"
<thorisporn@worldnet.att.net> wrote:


As a follow-up to my first post, the general response is that my
supposition
is untestable and not supported by data. So here is a reiteration of
"known"
facts.

1. The first placental (I repeat placental, placental, placental)
mammals
are from 85-90 mya. Is it coincidence that the decline in the number
of
dinosaur species began about that time? It sounds suspicious to me.
2. In all probability some meteor struck the Earth 65 mya and had
climatic
effects. From what I had read, the dinosaur record ceases some 100,000
years
before the KT boundary. Now, SJGould has stated that later excavations
reveal the presence of dinosaurs, ammonites etc. up until doomsday. So
what?
As far as the fossil record goes, the Cretaceous critters were in
_serious_
decline for quite awhile before the meteor crash. What caused that
decline.
Weren't the latest Cretaceous mammals increasing in size?
3. Long ago, giants walked the Earth oblivious to the small beasties
that
would be their successors. The big guys were the Therapsids and their
competition were Thecodonts. No one has a problem accepting this. Why
is
there a problem with mammals eating Dinosaur young?
4. As far as the fossil record is concerned, Therapsid fossils cease
and
Dinosaur fossils begin about the same time in the Triassic. It seems
plausible that some Herrerosaur chased a pack of Cynonathus away from
a dead
Dicynodont thereby causing the pups to starve. Apart from changing
fossils
there is no evidence that Therapsids died out from competition with
Thecodonts. But it seems implausible that there was no competition
between
the two types. What would be considered "evidence" that Thecodonts
caused
the demise of Therapsids?
5. It is accepted that Molluscs caused the decline in Brachiopods.
What
"evidence" would demonstrate this? How can this belief be tested?
6. Lots of species and genera have been forced into extinction from
competition with other lifeforms.This is the case for
Multituberculates,
Trilobites, Creodonts to name a few. The Dinosaurs, however, would
have
"reigned" until now had it not been for a fortuitous meteor. They were
oddly
immune from competition.
7. Small animals _can_ kill large ones. Watch enough nature flicks and
you'll come across the episodes where a pack of Hyenas is in the
process of
killing an infant Rhinoceros.