*New in February 2011: slice movies, dynamic cutaways and inspeCTor!
The imagery on this page is the basis for a paper entitled Craniofacial morphology of Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar by N.J. Kley, J.J.W. Sertich, A.H. Turner, D.W. Krause, P.M. O'Connor and J.A. Georgi (2010, Journal of Vertebrate Paleontology, 30(s1):13-98). The Abstract is as follows:
Simosuchus clarki is a small, pug-nosed notosuchian crocodyliform from the Late Cretaceous of Madagascar. Originally described on the basis of a single specimen including a remarkably complete and well-preserved skull and lower jaw, S. clarki is now known from five additional specimens that preserve portions of the craniofacial skeleton. Collectively, these six specimens represent all elements of the head skeleton except the stapedes, thus making the craniofacial skeleton of S. clarki one of the best and most completely preserved among all known basal mesoeucrocodylians. In this report, we provide a detailed description of the entire head skeleton of S. clarki, including a portion of the hyobranchial apparatus. The two most complete and well-preserved specimens differ substantially in several size and shape variables (e.g., projections, angulations, and areas of ornamentation), suggestive of sexual dimorphism. Assessment of both external and internal morphological features indicates a habitual head posture in which the preorbital portion of the dermal skull roof was tilted downward at an angle
of ~45°. Functional and comparative assessment of the feeding apparatus strongly indicates a predominantly if not exclusively herbivorous diet. Other features of the craniofacial skeleton of S. clarki are consistent with the interpretation developed from analysis of the postcranial skeleton of a terrestrial habitus, but the current working hypothesis of a burrowing lifestyle is not supported. The atypical appearance of the skull and lower jaw of S. clarki is underscored by the identification of at least 45 autapomorphic features, many of them related to the greatly foreshortened snout.
About the Species
This skull (UA 8679) was discovered by L. L. Randriamiaramanana, southeast of the village Berivota, Mahajanga Basin, in northwestern Madagascar; Maevarano Formation, Upper Cretaceous. It was made available to the University of Texas High-Resolution X-ray CT Facility for scanning by Dr. David Krause of the Department of Anatomical Sciences, State University of New York at Stony Brook.
About this Specimen
The specimen was scanned by Matthew Colbert on 13 August 2003 along the coronal axis for a total of 999 slices. Each 1024x1024 pixel slice is 0.131 mm thick, with an interslice spacing of 0.131 mm and a field of reconstruction of 121 mm.
Buckley, G.A., Brochu, C.A., Krause, D.W., and Pol, D. 2000. A pug-nosed crocodyliform from the Late Cretaceous of Madagascar. Nature 405:941–944.
Kley, N.J., Sertich, J.J.W., Turner, A.H., Krause, D.W., O'Connor, P.M., and Georgi, J.A. 2010. Craniofacial morphology of Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar. Journal of Vertebrate Paleontology 30 (s1):13-98.