Re: The Holy of Holies... Dinosauria II

[Ken Carpenter <KCarpenter@dmns.org>]

don't forget the abnormally long diastema.

Kenneth Carpenter, Ph.D.
Curator of Lower Vertebrate Paleontology &
Chief Preparator
Dept. of Earth Sciences
Denver Museum of Natural History 
2001 Colorado Blvd.
Denver, CO 80205

Phone: (303)370-6392
Fax: (303)331-6492
email: KCarpenter@DMNS.org

For fun: http://dino.lm.com/artists/display.php?name=Kcarpenter

>>> "Jonathan R. Wagner" <jonathan.r.wagner@mail.utexas.edu> 14/Oct/04 >>>
HP Holtz wrote:

>Hadrosauridae by Horner, Weishampel & Forster (Anatotitan copei sunk into
>Edmontosaurus annectens!?! Urk!)

         Yup, I just found out about this a couple months ago. The authors 
suggest that the big ducks are just Edmontosaurus annectens with 
dorsoventrally compressed skulls. I haven't spoken to Brett-Surman about 
this yet, but I am skeptical. Our paper on postcrania addresses this issue, 
and comes to the conclusion that "Anatotitan copei is [...] diagnosed by a 
dramatically thin prepubic neck (9% of prepubis length), dorsoventrally 
squat cranium and quadrate, and slightly elongate skull." Because sample 
sizes are so small, the first character, and arguably the last as well, is 
debateable. Therefore, the diagnosis rests most firmly on the short 
quadrate. It is therefore no surprise that Horner et al. base their 
conclusion on the suggestion that the quadrates of the relevant specimens 
are crushed. I have not examined the quadrates up-close and personal, so I 
cannot address this myself. However, I really look forward to seeing the 
evidence that supports the suggestion that there are four quadrates on two 
specimen that are all crushed by nearly the same amount! if this is the case.

         Anyway, copei is probably closer to annectens than to regalis (if 
the latter two are distinct species), and so "Anatotitan" is begging to be 
sunk. Alternately, the wonderful epithet Anatosaurus could be resurrected 
for annectens, although I personally oppose generic proliferation.

Wagner