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Byronosaurus jaffeiFossil, Theropod Dinosaur
Dr. Peter J. Makovicky - Field Museum of Natural History
Dr. M. A. Norell, Dr. J. M. Clark, and Dr. T. Rowe
Byronosaurus jaffei
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Institute of Geology, Mongolian Academy of Sciences (IGM 100/983) - holotype

Image processing: Dr. Ted Macrini
Image processing: Dr. Amy Balanoff
Publication Date: 19 May 2003

Views: rostrum | braincase


Abstract from Makovicky et al. (2003):

"The troodontid Byronosaurus jaffei is known from two specimens from adjacent localities in the Nemegt Basin, Mongolia. These specimens are composed of well-preserved cranial material and fragmentary postcrania. Byronosaurus jaffei is included in a comprehensive phylogenetic analysis of Coelurosauria to ascertain its relationships. Several interesting characters of Byronosaurus jaffei have implications both for theropod relationships and for understanding patterns of variation within coelurosaurian theropods. These include the position of a foramen that marks the exit of the supra-alveolar canal (which we suggest is homologous with the subnarial foramen), the flattened internarial bar, the unusual interfenestral bar, and the unserrated teeth. Additionally, the well-preserved braincase allows detailed comparison with other troodontid taxa."

CT scans of the rostrum of IGM 100/983.
About the Species

This specimen, the holotype, which consists of a rostral fragment, braincase, and several postcranial pieces, was collected from the Upper Cretaceous Djadokhta Formation of Ukhaa Tolgod, Mongolia. It was made available to The University of Texas High-Resolution X-ray CT Facility for scanning by Dr. Mark Norell of the American Museum of Natural History. Funding for scanning was provided by an NSF grant to Dr. Norell.

The rostrum of the holotype specimen IGM 100/983 in right lateral and dorsal views.
About this Specimen

This specimen was scanned by Richard Ketcham and Timothy Rowe in May 1997 along the coronal axis for a total of 150 slices. Each slice is 0.2 mm thick, with an interslice spacing of 0.2 mm and a field of reconstruction of 22.7 mm.

About the

Mackovicky, P. J., M. A. Norell, J. M. Clark, and T. Rowe. 2003. Osteology and relationships of Byronosaurus jaffei (Theropoda: Troodontidae). American Museum Novitates 3402:1-32.

Norell, M. A., P. J. Makovicky, and J. M. Clark. 2000. A new troodontid theropod from Ukhaa Tolgod, Mongolia. Journal of Vertebrate Paleontology 20:7-11.

& Links

None available.


To cite this page: Dr. Peter J. Makovicky, Dr. M. A. Norell, Dr. J. M. Clark, and Dr. T. Rowe, 2003, "Byronosaurus jaffei" (On-line), Digital Morphology. Accessed February 23, 2018 at http://digimorph.org/specimens/Byronosaurus_jaffei/braincase/.

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