VARIETY AND IDENTIFICATION OF THEROPOD TEETH FROM THE EARLY JURASSIC HANSON FORMATION OF THE CENTRAL TRANSANTARCTIC MOUNTAINS

Theropod teeth are commonly found in the fossil record because teeth are the densest type of bone, and the relatively greater density gives the teeth a better chance of surviving the erosional process. However, despite specimen abundance, theropod dentition research is limited because teeth do not possess enough information to identify the species of the dinosaur. Here I describe the qualitative and quantitive dimensions of six isolated theropod teeth (A-F) from the Jurassic Hanson Formation of the Transantarctic Mountains. They were found in the same bonebed as Cryolophosaurus ellioti (Dinosaurua: Theropoda; Hammer, 1994) and the teeth were originally presumed to belong to this early theropod. Each tooth was anatomically measured and the dimensions recorded were entered into PAST®. The morphometrics (principal component analysis) of the six unidentified specimens were layered on top of other theropod dentition data, therefore a comparison could be made. Next, the six specimens were embedded in a clear epoxy and cut in the transverse and longitudinal direction to expose the enamel of the tooth. Enamel of each tooth was photographed using a Scanning Electron Microscope. Enamel analysis can definitively show that there are separate species within the unknown specimens if there are different growth patterns present. Combining morphometric analysis and the patterns of enamel structure can advance theropod dentition research, and utilize the plethora of specimens available. The results indicate that there are 2 groups of teeth: one presumed to belong to Cryolophosaurus ellioti and the other to a scavenger.