RE: T-rex Finger Count?

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

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Dinosaur World
>
> Hi everyone,
> I apologize in advance if this subject has been discussed prior to my
> joining the list.
>
> I read an article about a ?third digit? found on the hand of the Fort Peck
> Tyrannosaurus, but I have never heard anything since. Is there a consensus
> as to the validity of this claim?   And if so, will any of you Paleo-Artists
> and writers be inclined to make corrections or adaptations to your
> illustrations and works?

These reports come from a mistake over terminology. While it is true newly 
discovered specimens (e.g., Peck's rex) finally preserve
metacarpal III (already known from other tyrannosaurids, and inferred by 
Carpenter and Smith in their description of the T. rex
forelimb), it is ONLY the metacarpal. There was no digit associated with it. 
And, as a good metacarpal, it would be entirely within
the palm of the hand.

Also, at least some mounts of Peck's rex (e.g., the Maryland Science Center) 
inaccurately show it sticking off perpendicular to
mcII. This is almost certainly wrong. It was almost certainly appressed to mcII.

Hope this helps,

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
        Mailing Address:
                Building 237, Room 1117
                College Park, MD  20742

http://www.geol.umd.edu/~tholtz/
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796