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Re: Bird Competency
> Why mammals? Tell me if this is right: Diversity data over
>the Cretaceous shows a gradual decline of dinosaurs along with an
>increase of mammals. This doesn't prove causality, but it might
>be a hint.
Many organisms increased in diversity- angiosperms, for
example. There is not necessarily any causal connection. It also
seems unlikely that such supposedly intelligent mammals would take
over 150 million years to discover that eggs were edible or to
diversify to exploit this resource. Perhaps the biggest paradox
imposed by this hypothesis is the existence and diversification of one
of these "egg predators"- the monitor lizard, which itself should be
subject to predation by mammals.
It also is far from parsimonious to accept that not only did
mammals cause the extinction of dinosaurs, but that they did so
simultaneously (after 150,000,000 years of being completely
ineffective against reducing dinosaur diversity) the world over, in
North America, the Old World, and in island continents like South
America, India, Australia and the islands of New Zealand. Planning
among primitive mammals is unsubstantiated, the global mammal
conspiracy needed for such an occurrence, more so.
Eggs also have several advantages over live birth in large
animals, the most important probably being sheer volume of young. Egg
mortality could be (and juding from Maisaura colonies, probably was)
reduced by nesting close together in both time and space, flooding the
local predators with an abundance of food.