Boletín de la Sociedad Geológica Mexicana

Volumen 67, núm. 1, 2015, p.

Short note

The first record of Onchosaurus(†Sclerorhynchidae) from the Late Cretaceous of northern Mexico

Ariel Armando Delgadillo-Escobar1,*, Rubén A. Rodríguez-de la Rosa1,2, Adriana Ivonne Saenz-Quiñones3, Jesús Abraham Gutiérrez-Martínez3

1 Museo del Desierto Chihuahuense, Calle 7ª sur y Av. Nuestra Gente, Fracc. Valle Verde, CP. 33093, Cd. Delicias, Chihuahua, México.
2Universidad Autónoma de Zacatecas, Unidad Académica de Ciencias Biológicas, Campus II, Zacatecas, Zacatecas, México.
3 Museo de sitio paleontológico y ecológico, Rancho Don Chuy, Aldama, Chihuahua, México.

* This email address is being protected from spambots. You need JavaScript enabled to view it.



The fossil record of sclerorhynchid elasmobranchs in Mexico has been relatively scarce. In this paper we report a partial rostral tooth assigned to the cosmopolitan genus Onchosaurus (†Sclerorhynchidae), originally preserved in a shell-bed matrix, collected at the Potrero del Llano locality, municipality of Aldama, Chihuahua, Mexico. The specimen most likely came from the Upper Cretaceous San Carlos Formation. The tooth has morpho-anatomical features that allow its attribution to the species Onchosaurus cf. O. pharao, which has been previously described from localities in Egypt, Niger, DR of Congo, Angola, Syria, Japan, U.S.A., Brazil, Colombia and Peru. The rostral tooth represents the first record of Onchosaurusin Mexico and the fourth in North America, thus expanding its paleobiogeographic distribution.

Keywords: Chihuahua, Cretaceous, Batoidea, Sclerorhynchidae, Onchosaurus.