RE: ornithomimosaur

[Darryl Jones <dinoguy@sympatico.ca>]

At 03:27 AM 7/2/2002, Tracy L. Ford wrote:
> Well the thing is Bob Sullivan synonymized Ornithomimus edmontonensis with 
> Ornithomimus antiquus 1997
>
> Sullivan, R. M., 1997, A Juvenile Ornithomimus antiquus (Dinosauria:
> Thropoda: Ornithomimosauria), from the Upper Cretaceous Kirtland Formation 
> (De-Na-Zin Member), San Juan Basin, New Mexico: New Mexico Geological 
> Society Guidebook, 48th Field Conference, Mesozoic Geology and 
> Paleontology of the Four Corners Region, 1997, p. 249-253.

This seems a bit extreme, does it not?  I wish I had the paper to work from 
(I only have Glut's synopsis of Sullivan's point of view).  It seems a bit 
of a stretch to me to synonymize all of the species of Ornithomimus due to 
one tibial characteristic.  If anything, it should be generically 
significant, which would leave Ornithomimus antiquus as O. sp., due to the 
fact that it consists of only a partial hind limb.  I tend towards being a 
lumper, but this is a bit more than even I can handle.

Not only that, but O. antiquus being the only species from the 
mid-Campanian to the late Maastrichtian and living in places as far apart 
as New Mexico, Alberta, and the American East Coast also seems a bit 
much.  Why does O. sedens get to be a valid species, if it is only a sacrum 
and ilial arches (I hope I didn't invent a term)?  I realize that time and 
distance are not supposed to be the only characteristics separating 
species, but many of these specimens are fragmentary.

I was under the impression that someone was working on sorting out the 
Ornithomimidae.  Is this true, or am I nuts (yes, I realize both can be 
true, but I am talking about a specific case)?  There are several good 
specimens now available, complete with some un crushed skulls.  I had a 
look at the specimen in the picture a few years ago at the Tyrrell. What a 
beauty.  I wish they had also had the Struthiomimus skull on display, 
pictures of it are amazing.

Here's a throw away, is it possible that the type of O. velox is a juvenile 
tyrannosaur?  It has a (relatively) short metatarsus.  Brown(?) thought 
that the juvenile Albertosaurus specimens in the bone bed were 
ornithomimids. Man, would that ever mess up ornithomimid phylogeny.  Would 
that kill the name Ornithomimus?



Darryl Jones  <dinoguy@sympatico.ca>

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