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RE: correct this "definition"
> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu]
> On Behalf Of email@example.com
> Dougal Dixon writes in his encyclopedia "Complete Book of Dino's":
> The ruling reptiles are characterized by:
> * the number of bones in the skull
For loss of postfrontal bone, perhaps?
> * the presence of a flange on the upper arm bone that held
> powerful muscles
Dinos are characterized by an enlarged deltapectoral crest, yes.
> * three or fewer finger bones in the fourth finger
> * Three or more vertebrae fixed to the hip bones
In general, yes; but either reversed in a few Late Triassic forms or
independantly evolved in Ornithischia, Sauropodomorpha, Theropoda.
> * a hole rather than a socket in the hip for the leg bone
> * a small ball-like head on the thigh bone
Subrectangual inturned femoral head. Okay.
> * a strong joint between the foot bones and the bones of the hind leg
By which he means the mesotarsal ankle, maybe? That characterizes a larger
group than Dinosauria. If by this he means a broad (4x wider mediolaterally
than thick anteroposteriorally) metatarsal hinge surface, than yes.
> Note he has this on his dinosaur classification / tree page,
> but aren't the "ruling reptiles" the archosaurs? Anyway, if some of
> this is contrary to the current thought on what makes a dino
> a dino, please point it out.
> This came out in 2006 and is
> the most current dino book I've picked up out of the 20 or so I have.
Eh hem... http://www.geol.umd.edu/~tholtz/dinoappendix, available in stores
and online today... :-)
Thomas R. Holtz, Jr.
Email: firstname.lastname@example.org Phone: 301-405-4084
Office: Centreville 1216
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
Faculty Director, Earth, Life & Time Program, College Park Scholars
Mailing Address: Thomas R. Holtz, Jr.
Department of Geology
Building 237, Room 1117
University of Maryland
College Park, MD 20742 USA