The imagery on this page was the basis for a paper entitled The braincase of Apatosaurus (Dinosauria: Sauropoda) based on computed tomography of a new specimen with comments on variation and evolution in sauropod neuroanatomy, by A.M. Balanoff, G.S. Bever, and T. Ikejiri (American Museum Novitates 3677:1-32, 2010). The abstract is as follows:
We describe a previously unreported braincase of the sauropod dinosaur Apatosaurus from the Cactus Park Quarry, Morrison Formation of western Colorado using high-resolution X-ray computed tomography. The digital nature of these data allowed us to prepare and describe the first three- dimensional rendering of the endocranial space in this historically important dinosaur species. Results are compared with a range of taxa drawn from across the sauropod tree revealing previously underappreciated variation in the sauropod neurocranium. Examples of variable characters include the nature of cerebral and pontine flexure, morphology of the parietal body and superior sagittal sinus, division of the metotic fenestra, and the morphology of several cranial nerve foramina. We provide preliminary evolutionary hypotheses and discussion for many of these features. Hopefully, the recognition that phylogenetically informative variation is present will encourage more detailed descriptions of this anatomically complex region, as well as facilitating a synthetic review of the sauropodomorph braincase as these descriptions become available.
About the Species
This specimen was collected from the Jurassic Morrison Formation of the Cactus Park BYU Quarry in western Colorado. It was made available to the University of Texas High-Resolution X-ray CT Facility for scanning by Dr. Gabe Bever of the American Museum of Natural History. Funding for scanning was provided by Dr. Bever.
About this Specimen
This specimen was scanned by Richard Ketcham on 14 May 2004 along the coronal axis for a total of 127 slices. Each 1024 x 1024 pixel slice is 1.0 mm thick, with an interslice spacing of 0.8 mm (for a slice overlap of 0.2 mm) and a field of reconstruction of 265 mm.
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Click on the thumbnail to the left for a pitch rotation animation (1.4 mb) of the Apatosaurus endocast rendered inside the semi-transparent braincase.
Click on the thumbnail to the left for a yaw rotation animation (2.4 mb) of the Apatosaurus endocast rendered inside the semi-transparent braincase.