RE: how many species

["Michael de Sosa" <ofsosa@uclink4.berkeley.edu>]

From: Nick Longrich

> species of Allosaurus and one species of Ceratosaurus? Admittedly
> species diversity decreases with size, but if you look at North
> America's carnivore diversity before humans arrived:
>
> FELIDAE: bobcat, cougar, jaguar, Panthera leo atrox(extinct) and
> Smilodon(extinct).
>
> CANIDAE: red fox, grey fox, arctic fox, kit fox, coyote, wolf, dire
> wolf(extinct)
>
> URSIDAE: black bear, brown bear, polar bear, short-faced bear(extinct)

And besides the other felids the other Nick mentioned (lynx, ocelot,
Miracionyx and friends), this list doesn't even include tons of mustelids,
procyonids, amphicyonids ("bear-dogs"), nimravids, hyaenids (?) ... not to
mention possums, bats and other non-carnivoran carnivores (heh).

So we really shouldn't be all that surprised to see ridiculous numbers of
species of Allosaurus, Ceratosaurus, Torvosaurus, Stokesosaurus,
Marshosaurus, Ornitholestes, Coelurus, Koparion, and god knows how many
other theropods in the Morrison. Just look at the herbivores: four species
each of Diplodocus and Camarasaurus, three of Diplodocus and Stegosaurus,
two of Brachiosaurus and Camptosaurus, and this on top of a plethora of
other sauropods, small to medium ornithopods, and maybe even a
heterodontosaur!

I never understood why we like to cram all our theropods into one species
per genus.

Mike D.

PS - Did not mean any of the above to be a slight upon anyone.