Southeastern Section - 54th Annual Meeting (March 1718, 2005)
Paper No. 6-8
Presentation Time: 8:00 AM-12:00 PM

ANATOMY OF THE SKULL AND BRAINCASE OF A NEW DEINOSUCHUS RUGOSUS SPECIMEN FROM THE BLUFFTOWN FORMATION, RUSSELL COUNTY, ALABAMA

KNIGHT, Terrell K., Geology and Geography, Auburn Univ, 210 Petrie Hall, Auburn, AL 36849-5305, knightk@auburn.edu and SCHWIMMER, David R., Chemistry & Geology, Columbus State Univ, 4225 University Ave, Columbus, GA 31907

A well-preserved posterior skull of Deinosuchus rugosus, with an intact braincase, was discovered in the Upper Cretaceous (Campanian) Blufftown Formation in Russell County, Alabama. This new specimen enabled descriptive analysis of the braincase of this primitive alligatoroid and revealed favorable comparisons of cranioquadrate passages to the same region of Alligator mississippiensis. However, a modern A. mississippiensis shows more elongate supratemporal fenestrae and a gentler incline of the prefrontal ridge than D. rugosus. Due to the smaller size of this Deinosuchus skull compared with other eastern specimens, we conclude the individual was a juvenile.

An enigmatic Upper Cretaceous fossil from the Black Creek Formation of North Carolina, putatively a very large Deinosuchus braincase, was also compared with this new Alabama specimen. Similarities between the specimens are in the placement of the sutures, ridges, and foramina. From a posterior-ventral aspect, the fossil represents the left exoccipital and quadrate of Deinosuchus. The cranium of Deinosuchus rugosus has not been previously available for detailed study because of generally poor specimens, and the new information enhances the position of Deinosuchus in the basal phylogeny of Alligatoroidea.

Southeastern Section - 54th Annual Meeting (March 1718, 2005)
General Information for this Meeting
Session No. 6--Booth# 24
Sedimentary Geology and Paleontology (Posters)
Bayview Hotel at the Grand Casino Resort: Grand Ballroom D
8:00 AM-12:00 PM, Thursday, March 17, 2005

Geological Society of America Abstracts with Programs, Vol. 37, No. 2, p. 12

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