Re: Biogeographic origin of Diplodocidae

["Thomas R. Holtz, Jr." <th81@umail.umd.edu>]

At 11:13 AM 9/17/98 +0100, Octávio Mateus wrote:
>
>       During the Late Jurassic, camarasaurids and diplodocids were restricted 
> to
>Laurasia, while dicraeosaurids and titanosaurids were restricted to
>Gondwana. The occurrence of these sauropod taxa outside their presumed area
>could be interpreted as the result of dispersal events. 

Actually, although camarasaurids are not known from Tendaguru, they have
been reported from the Late Jurassic of Zimbabwe (a paper by McIntosh &
Raath about ten years ago or so: I have to look it up).

Also, the Tendaguru "Barosaurus" material does demonstrate that Late
Jurassic diplodocids were present in Gondwana.

So, neither of these groups were "restricted" to Laurasia, although (as you
note) their diversity and/or abundance seems to be higher there than in
Gondwana.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:tholtz@geol.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661