, Volume 93, Issue 5, pp 242–245

An abelisaurid from the Late Cretaceous of Egypt: implications for theropod biogeography

Short Communication

DOI: 10.1007/s00114-006-0092-3

Cite this article as:
Smith, J.B. & Lamanna, M.C. Naturwissenschaften (2006) 93: 242. doi:10.1007/s00114-006-0092-3


Recent paleogeographic scenarios postulate the isolation of continental Africa during the Late Cretaceous. The absence of abelisaurid theropods from Upper Cretaceous African strata was offered as support of hypothesized African isolation with the acknowledgement that the paucity of African abelisaurids may be mostly an issue of sampling. Here we report on a shed theropod tooth from the Upper Cretaceous (Maastrichtian, ∼70 Ma) Duwi Formation of Egypt. The tooth was referred to the Malagasy abelisaurid “Megalosauruscrenatissimus (=Majungasauruscrenatissimus) in 1921. A discriminant function analysis was run to test for morphological congruence between the Egyptian tooth and the dentitions of 24 theropod taxa. The analysis correctly classified 96.6% of the teeth in the sample and assigned the tooth to Majungasaurus. As current paleogeographic reconstructions posit Madagascar had attained its current position relative to Africa before the Late Cretaceous, it is unlikely that the Egyptian tooth actually pertains to Majungasaurus. Nevertheless, its classification as an abelisaurid supports its referral to the clade. This tooth thus constitutes defensible evidence of an abelisaurid from the post-Cenomanian Cretaceous of mainland Africa. Combined with recent discoveries of abelisaurids in Niger and Morocco, the result indicates that Abelisauridae was a diverse group in Africa during the Cretaceous, existing in multiple places for at least ∼25 Ma and weakens support for hypotheses of an isolated Africa during the Late Cretaceous.

Supplementary material

114_2006_92_MOESM1_ESM.gif (21 kb)

Theropod dental anatomy and variables used in this study (modified from Smith et al. 2005).A, Crown in lateral view showing apical length (AL, measured along line segment AG (points A,B, and G defined by Smith et al. 2005)); crown angle (CA, angle GAB); crown base length (CBL, measured along line segment AB at the base of the enamel); crown height (CH, measured from apex to the base of the enamel along line segment GB); mesial apical (MA), mesial midcrown (MC), and mesial basal (MB) denticle densities (measured along the mesial carina); distal apical (DA), distal mid-crown (DC), and distal basal (DB) denticle densities (measured along the distal carina). B, the crown in (A) in basal view showing CBL and crown base width (CBW, measured perpendicular to CBL)

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114_2006_92_MOESM2_ESM.pdf (123 kb)
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Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  1. 1.Earth & Planetary SciencesWashington UniversitySt. LouisUSA
  2. 2.Vertebrate PaleontologyCarnegie Museum of Natural HistoryPittsburghUSA