Re: Tiktaalik

["T. Michael Keesey" <keesey@gmail.com>]

On 4/6/06, Tim Williams <twilliams_alpha@hotmail.com> wrote:
> This experimentation lasts until an evolutionary "tipping point" is reached,
> when the body plan becomes committed to a given ecomorphology (locomotory
> style, in these cases), and there's no way back.

Plesiosaurs, placodonts, icthyosaurs, spheniscids, choristoderans,
mosasauroids, chelonids, cetaceans, pinnipeds, sirenians ...

Or, for avialans: patagopterygids, phorusrhachids, diatrymatids, ratites ...

Better examples would be pterosaurs and bats, where there really
wasn't any locomotory reversion  (that we know of, anyway).
--
Mike Keesey
The Dinosauricon: http://dino.lm.com
Parry & Carney: http://parryandcarney.com