Db_abstract

New evidence of cannibalism in the Late Triassic (Apachean) dinosaur Coelophysis bauri (Theropoda: Ceratosauria)

Discusses small Coelophysis bones found in fossilized intestinal contents, feces and vomit from larger Coelophysis. This provides new evidence of cannibalism in Coelophysis.

Item Details

Abstract

At least three Coelophysis bauri specimens from the New Mexico Museum of Natural History's Late Triassic Whitaker (Coelophysis) Quarry block (C-8-82) from Ghost Ranch, NM have cololites (fossil gut contents) and/or coprolites directly associated with articulated skeletal material. The cololites and coprolites occur between the ischia and the proximal caudal vertebrae and postero-ventral area. Most of the coprolite material is formless and was apparently somewhat mixed with wet mud and silt at or near the time of death and burial. In one of the specimens (NMMNH P-44552) the coprolitic material contains hundreds of mm-to-cm-size bone fragments including long bone and rib fragments, wrist bones, and thin sheets similar to skull or pelvic bone. Proximal metacarpals, an ulnare, and partial phalanges were prepared from the coprolite and are indistinguishable from those of C. bauri, thus providing new and compelling evidence of cannibalism in the species. Assuming that Coelophysis was cannibalistic under stress, as are some modern reptiles, the passage of cannibalized juvenile bones completely through the gut probably indicates that the Ghost Ranch Coelophysis were under stress for some time prior to death.


Another Coelophysis specimen, NMMNH P-44801, has a small amount of coprolite material containing sparse bone fragments. The cololite and coprolite material associated with a third specimen, NMMNH P-42352 is enigmatic; it consists of a few small bone fragments in a densely packed matrix of small (~1 mm long, by ~0.1 mm diameter), rod-shaped material.