[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Bzzzzzzzzzzz (was Re: Mongolian troodontids)




Free access to heaps of AMNH papers!

http://diglib1.amnh.org/novitates/

Thanks David. One paper in particular caught my attention:

Engel, M.S. (2003). A new interpretation of the oldest fossil bee (Hymenoptera: Apidae). Am. Mus. Novit. 3296: 1-11.

The 65 MYA eusocial stingless bee _Trigona prisca_ is put in its own genus _Cretotrigona_. Its place in apid phylogeny indicates that bees diversified long before the end of the Cretaceous.

This got me thinking... a lot has been said lately about a "trees down" origin of flight, courtesy of the evidence for gliding and scansoriality in _Microraptor_. But maybe avian flight did evolve from the "ground up", among theropods that leaped into the air against insects. However, the target was not flying insects, but their combs and nests. This removes the difficulty of explaining how small cursorial theropods could have outmaneuvered flying insects. Combs and nests offered a stationary target - as did spiders' webs, or arthropods just sitting on leaves.

Again, I don't want to breathe life into the old "ground-up" vs "trees-down" debate. I think the ancestors of birds divided their time between both ground and the trees, and both played a role in fostering the development of the wing. Maybe "Proavis" was an opportunist, and leaped from either the ground or a tree-branch, depending upon what was more convenient.



Tim



_________________________________________________________________
Add photos to your e-mail with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/featuredemail