Re: Name the dino

[Mickey Mortimer <Mickey_Mortimer111@msn.com>]

Amtoine Grant wrote-

I just came across this article on the net and I don't have a clue
which theropod they're talking about. The pointy, scissor-like jaw
conjures up a spinosaur, but I haven't heard of this many specimens.
Anybody else?

It's-

undescribed carcharodontosaurid (Coria and Currie 1997)
Late Cenomanian, Late Cretaceous
Huincul Formation of Rio Limay Subgroup, Argentina
Material- (MUCPv coll.) (8 m; adult) maxillary tooth, surangular, dorsal
vertebrae, dorsal ribs, caudal vertebra, manual ungual, acetabular region of
ilium, pubes, femora, tibiae, fibula, metatarsal, several pedal phalanges
(MUCPv coll.) seven other individuals
Comments- This taxon was discovered in 1995, but only reported to Coria in
1997, when he and Currie examined the material. It was announced at that
years Society of Vertebrate Paleontology meeting, and described briefly in
an abstract (Coria and Currie, 1997). At the time, only the remains of an 8
meter long specimen were known, and it was identified as an adult. The teeth
are described as carcharodontosaurid-like, and the femur noted to share
characters with Giganotosaurus (eg. dorsally projected head; “deep sulcus”).
Coria and Currie returned to the site in 1998 to discover the presence of at
least six individuals, some of which Currie says could be larger than
Giganotosaurus’ holotype. The association of several individuals was
suggested to be due to pack behavior. This was reported to the popular media
in May 1999, and later described in another abstract (Eberth et al., 2000).
Later (Eberth and McCrea, 2001), the minimum number of individuals was
increased to eight. This paper finds the probable cause of death to be
drought and notes the bones experienced at least two flooding events and
were exposed and trampled over more than one season. However, they state
several alternatives exist besides gregarious behavior to explain the find,
including environmental stress and breeding. It was reported on the internet
that a magazine had termed the taxon Giganotosaurus “argentine”, but this
has yet to be confirmed and would be a nomen nudum in any case. Currie and
Coria are of the opinion it is a new genus, and though the description
(sometimes rumored to be in Nature or Science) is often said to be nearly
completed, it has yet to appear.
References- Coria and Currie, 1997. A new theropod from the Rio Limay
Formation. Journal of Vertebrate Paleontology. 17(3) 40A.
Eberth, Currie, Coria, Garrido and Zonneveld, 2000. Journal of Vertebrate
Paleontology. 20 (3).
Eberth and Crea, 2001. Were large theropods gregarious? Jourtnal of
Vertebrate Paleontology. 21(3) $6A-47A.

Mickey Mortimer
Undergraduate, Earth and Space Sciences
University of Washington
The Theropod Database - http://students.washington.edu/eoraptor/Home.html