RE: New dinosaur from South America

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

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Steve Brusatte
>
> Yeah, I read about this earlier and am in the process of writing
> a short news report for my site.
>
[snip]
>
> Maybe Dr. Holtz knows more about this.
>

Okay, here's some of what I know about the big new carcharodontosaurine from
Argentina:

I) It has not been formally named.  I know that Currie & Coria HAVE a name
picked out, but I don't know what it is (and would be obliged to keep it a
secret anyway).

II) It was separated from _Giganotosaurus_ by a couple of million years.
Some brief Rio Limay Fm. stratrigraphy:

The Rio Limay Formation contains three members: the Albian Candeleros
Member, the Albian-Cenomanian Huincul Member, and the Cenomanian-Turonian
Lisandro Member.

_Giganotosaurus_, _Andesaurus_, and _Rebbachisaurus tessonei_ are from the
Candeleros Mbr; this new caracharodontosaurine and _Argentinosaurus_ are
from the overlying Huincul Mbr; I *think* the other new titanosaurian is
from this member as well..

III) Word has it that the multiple specimens of different growth stage of
the new carcharodontosaurine are found on the exact same sedimentary
horizon; Coria & Currie interpret this (and other sedimentological evidence)
as indiciating that these individuals were buried simultaneously, which
suggests that they were living together (at least during the last minutes of
their life) as a group, which suggests in turn that *on at least some
occassions* multiple aged individuals (members of the same family?) did live
together.

Hope this helps.

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-314-7843
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