RE: Spinosaurus's sail

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of Tracy L. Ford

I just looked at my drawing of Spinosaurus and was wondering why mine and B. Krzic. Then it dawned on me, the angle of the neural spines. He has them all drawn vertical, in stromer many of them are angled forward. I don’t believe that they were modified during fossilzation. Sereno also has them drawn vertical, which I think is incorrect. I believe (as do some others) that the front dorsal neural spines tilted slightly forward, than went vertical. Some back ones even have a slight curve to them.

 

Tracy L. Ford

P. O. Box 1171

Poway Ca  92074

 

I was waiting for someone to comment on that... :-)

 

Yeah, Stromer shows that some of the anteriormost (and posteriormost?  Can't recall if they are known) of the parts of the sail are curved anteriorly (and posteriorly?).  In this sense they more closely resemble the spines of Edaphosaurus than Dimetrodon, and furthermore are dissimilar to the hump-supporting structures in mammals.

 

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742      
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