Re: Late J Heterodontosaurs (was Re: Sereno's Prosauropoda)

[Dinogeorge@aol.com]

In a message dated 7/8/99 3:09:12 PM EST, th81@umail.umd.edu writes:

<< In his 1997 paper in Annual Review of Earth and Planetary Sciences (25:
 435-489), Sereno considers the Late Jurassic English dinosaur _Echinodon_ a
 heterodontosaurid (as he earlier suggested in JVP 11: 168-197).  The
 heterodontosaurid features of _Echinodon_ have not been published yet, to my
 knowledge. >>

I published on heterodontosaurid features of Echinodon in my article on 
Heterodontosauria for Gakken in Dino-Frontline #8, 1994:

Olshevsky, G., 1994. "The Origin and Evolution of the Heterodontosaurians," 
Kyoryugaku Saizensen [Dino-Frontline] 8: 74?97 [illustrations by T. L. Ford; 
in Japanese].

It's also the only place you'll see a figure of the dentary of the Fruita 
"Echinodon" discovered by George Callison in Colorado about a decade or so 
ago and still undescribed. Maxillary and dentary "fangs" are 
heterodontosaurian features of Echinodon, although the pattern is somewhat 
different from that of Heterodontosaurus and other heterodontosaurids and 
Goyocephale and other pachycephalosaurians. I go into the idea that 
heterodontosaurians are not basal ornithopods as almost everyone else thinks 
but are basal marginocephalians. I think this idea first comes up in Zhao 
Xijin's infamous 1983 paper with all the undescribed dinosaurs, and also 
harkens back to Santa Luca's 1980 paper on the postcrania of 
Heterodontosaurus, in which he notes enough postcranial differences between 
Heterodontosaurus and ornithopods to question the then-current placement of 
Heterodontosaurus in Ornithopoda.