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(fwd) Mammals as a cause of Dinosaur extinction
On 16 Dec 1997 05:49:02 -0500, "Stan Engel"
((I posted this previously in another news group))
Why does Stephen Jay Gould completely ignore the possibility that
may have been a factor in the extinction of the dinosaurs some 65 mya.
Instead, he says that mammals and dinosaurs co-existed throughout the
Jurassic and Cretaceous and that this demonstrates that mammals did
consume the Dinosaur young leading to the demise of that group. I
this theory from a 1950's textbook.
Giant reptiles (turtles) have "ruled" the Galapagos islands for a long
time. It is my understanding that recently imported dogs and cats have
caused a decline in the turtle population due to their predation of
hatchlings. The same predation has also reduced the population of the
Galapagos "rulers", the Iguanas. Why is it not a feasible possibility
newly evolved (Late Cretaceous that is) placental mammals damaged the
dinosaur population by eating their young. The adult Dinosaurs (just
adult Galapagos turtles) would be invulnerable to mammal attack but
young would not be so lucky. Question--- When did definable placental
mammals evolve? Was it not in the Late Cretaceous, at about the same
that the number of Dinosaur species declined?
Newly imported mammal species also exterminated the "rulers" of
the Dodos, some 3 centuries ago and seem to be doing the same today to
ruling Tuataras, Kiwis and Parrots of New Zealand. In addition, it is
understanding that the largest predator of the Paleocene (post
was the 2 metre tall Diatryma which was eventually superseded by
Creodonts and true carnivores. Is my understanding correct? If
destroyed by placental mammal competition why not Troodonts or
I do not claim that mammals were the sole or even a major cause of
extinction. I believe that it was a factor and should not be summarily