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Based on cranial elements, Maisey (1987) erected Egertonodus. The teeth of this genus were described by Rees and Underwood (2008); they noted a cusp with a flattened labial face, a strong cutting edge, weak folds of the lower crown face and multiple slender cusplets. They provided a range of Bathonian to Barremian/Aptian of England for the genus.
Bourdon et al (2011) reported a single tooth from the Santonian of New Mexico which they argued compares better with the Egertonodus design than the common hybodontid from the Point Lookout Sandstone Meristodonoides.
As there is only a single specimen and the presence of this tooth-design would greatly expand the geographic and temporal range of the genus, it was included as ?Egertonodus.
Selected References
Bourdon, J., Wright, K., Lucas, S.G., Spielmann, J.A. and Pence, R., 2011. Selachians from the Upper Cretaceous (Santonian) Hosta Tongue of the Point Lookout Sandstone, central New Mexico. New Mex. Mus. Nat. His. and Sc., Bulletin 52; 54pp.
Maisey, J.G., 1987. Cranial anatomy of the Lower Jurassic shark Hybodus reticulatus (Chondrichthyes: Elasmobranchii), with comments on hybodontid systematics: American Museum Novitates, n. 2878, p. 1-39.
Rees, J. and Underwood, C., 2008. Hybodont sharks from the English Bathonian and Callovian (Middle Jurassic): Palaeontology, v. 51, p. 117-147.
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