Results of a high resolution CT-scan of Coelophysis bauri (Upper Triassic Chinle Formation, New Mexico)

Describes the use of CT scanning to reconstruct the braincase of Coelophysis.

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A recently prepared skull of the ceratosaurian theropod Coelophysis bauri (Upper Triassic Chinle Formation of Ghost Ranch, New Mexico) in the collection of the Cleveland Museum of Natural History was CT-scanned in Chicago. Charles Smith of BIR Laboratories used an industrial CT scanner to scan the specimen. Approximately 600 transverse sections were taken 0.5 millimeters apart to image the complete skull and first three cervical vertebrae. This specimen is well-preserved and shows less distortion than is typical for Coelophysis from this site. The occipital region is undistorted. The goal of this project was to extract a braincase and clarify the internal cranial anatomy of a basal theropod.

The scan resulted in good separation between the bone and the matrix in most regions except for the skull roof. Bones from this area were filled in by a laser scan. Elsewhere, it was possible to reconstruct the internal anatomy. The anatomy of the braincase and endocranium is presented with comparisons of the related form, Syntarsus rhodesiensis from Zimbabwe, and the tetanurine theropod, Allosaurus fragilis from Utah and Colorado.