Re: Ostrom in Colorado

[Kata McCarville <kmccarvi@basalt.Mines.EDU>]

If you don't want to hear about Archeopteryx and birds, delete  
this right now!

Just to comment a bit further on John Ostrom's visit to  
Colorado...as Abbott said here, Ostrom has casts of all 7  
Archies at Yale, and I think that's the only place that does.

I also saw the lecture on the School of Mines campus last  
Thursday afternoon. It was mostly about osteology, and the  
evolution of the muscle/tendon (supracoracoideal) that goes  
through the intraossial canal. That muscle attaches to the top  
of the humerus, and it is for supinating the wing during the  
recovery stroke of flight. Archie didn't have this, but even in  
modern birds, you can sever the attachment, and the bird can  
still fly.

I saw the "lunate carpal" that we've talked about in this group.  
It's sort of a three-dimensional phenomenon, which might be why  
it's hard to see in some orientations. In the highly developed  
state in more modern birds, it looks a lot like a one-sided  
artiodactyl tarsus--a deep groove with one high process  
(represented by the lunate bone in Archie) defining it. Unlike  
in artios, the groove is at an angle, maybe to facilitate the  
rotation of the wing in the flight stroke, or during other  
activities (as Lipps and Cowan have suggested, fighting and  
display...and as I looked at the diagrams and fossils and  
drawings--I began to believe.)

He did show the "insect trapping" diagram again, that shows  
Archie grabbing or knocking insects out of the air with the  
wings.

And the stuff about the long legs meaning cursorial (roadrunner,  
secretary bird)--what about quail, which are cursorial but have  
pretty short legs, and wading birds, which aren't exactly  
cursorial but have long legs...oh well.

I also got to walk Dinosaur Ridge (Jurassic bones and tracks,  
Cretaceous tracks) with Dr. Ostrom, Martin Lockley, Adrian Hunt,  
Bob Weimer (not dinos, but stratigraphy) and a number of other  
fairly well known folk on Saturday (be still my beating  
heart...).

He says Archie #7 has an ossified sternum, but is also smaller  
than all the other Archies. So, it might imply some things about  
size and age, but only if you think the sternums from the other  
6 Archies are missing because they were cartilaginous.

He says he'll be looking for fused vertebrae in Confuciornis  
when he gets a chance. He expressed some doubt about the age on  
the Chinese specimens, based on the fact that there's been  
considerable controversy about the dating of the rocks even  
before the discovery of the fossils--that there's a possibility  
they may not be much (any?) younger than say, Hesperornis. 


Kata McCarville
Colorado School of Mines