Re: Theropod of Patagonia

["Mickey Mortimer" <Mickey_Mortimer111@msn.com>]

Thomas Hammann wrote-

> anything new about the pack of giant theropods found by Currie in
Patagonia some years ago? It seemed to be the biggest predatory dinosaur
species ever found if I remember correctly.

Ha!  I wrote a summary of this taxon a while ago for just such an occasion.
Note I have yet to find anything saying this taxon definitely got larger
than known Giganotosaurus individuals.  Also, if anyone has photos from the
RTMP website that documented the excavation by Coria and Currie (the
website's been subsequently destroyed), I would appreciate them.

undescribed carcharodontosaurid (Coria and Currie 1997)
Cenomanian, Late Cretaceous
Huincul Member of the Rio Limay Formation, 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