RE: Deinonychus claw use...

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

> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] 
> On Behalf Of brushes2@juno.com
>
> John Ostrom  would have loved this paper! 
>  Alan

He would have, indeed!!

By the way, any enterprising student (or other!) with access to advanced 
troodontid jaws with teeth in them, I offer the following
short project:

The authors state:
"The teeth of troodontids are similar to those of dromaeosaurids in that 
denticles are reduced or absent on the anterior carina,
with large hooked denticles on the posterior carina [66], [67]. Troodontid 
denticles appear proportionally much larger than those of
dromaeosaurids, and compared to the crown height this is true. However, 
troodontids possessed many more teeth in their jaws than
would have a similarly sized dromaeosaurid [67]. For a given fixed jaw length, 
troodontid teeth are comparatively much reduced in
size; the crown height of troodontid teeth would have been only about half as 
much as those of a dromaeosaurid. Therefore it is
probably more accurate to say that troodontids do not have large denticles; 
rather, they have short crowns, with similarly sized
denticles as might be expected for a dromaeosaurid of similar body mass. This 
makes sense if denticles have a size below which they
are no longer able to function effectively."

So, a test of this:
Measure denticle size in troodontid teeth (and dromaeosaurid teeth, and a 
couple other basal groups for comparison) AND the length
of the tooth row of the same individual. Plot the two against each other.

If the Fowler et al. hypothesis is correct, the troodontid and dromaeosaurid 
data will plot with each other. Alternatively, it may
be that the the enlarged denticle size in Troodon et al. will continue to scale 
above that of dromaeosaurids even when plotted
against tooth row length rather than a measure of tooth size.

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661               

Faculty Director, Science & Global Change Program, College Park Scholars
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA