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Larry Martin/Jack Horner "Debate"



On Sunday, March 21, The Natural History Museum of L.A. County hosted 
a two hour debate between Martin and Horner on the subject "Did Dinos 
Soar?"  Since a notice of the impending event was posted on list, I thought 
I'd submit a thumbnail review of it.  

For the most part, the debate was a no-show.

Apparently, Kevin Padian originally had been lined up to present the views of 
the Birds-from-Dinosaurs camp.  His apparent withdrawl resulted in 
Horner being drafted as a substitute -- and practically an unwilling one at 
that.   Horner claimed (or feigned) no particular interest in the subject of
avian-dinosaur relationships. When he wasn't being jocular or self-effacing,
Horner
was playing for broad laughs as when he donned a dinosaur hand-puppet and
growled during Martin's presentation and with his inclusion of a picture from 
"The Lost World" to illustrate theropod behavior.

Martin's case against a dino-bird relationship revolved around the contentions
that (a) Sinosauropteryx's feathers are collagen fibers, (b) the three-
fingered 
theropod manus is comprised of digits 1-2-3 while the birds' is 2-3-4 and (c)
the semilunate carpals of birds and dinosaurs are striking dissimular (sorry--
the slides comparing these features of birds and dinosaurs were so miniscule
and murky that I don't feel competent to represent his points.)  Martin
said that he had been told by one of the Chinese scientists that they'd 
recovered a Sinosauropteryx specimen with a skin impressions, and Martin 
felt that the specimen would put to rest the issue of the presence of feathers
when and if they're produced (sic).

In the rebuttal period, Horner recapped his histology work and displayed
slides 
of longitudinal sections of the ends of bird and dinosaur limbs showing a 
striking similarity in the characteristics of "cartilage and marrow canals"
(i.e.
canals arising in the cartilaginous material penetrate the bone and join with 
marrow canals)-- and the absence of this feature in crocodilian bones.