New records of Mathoceras Casey (Deshayesitidae, Ammonoidea) from the Aptian (Lower Cretaceous) of Mexico and Hungary: Biostratigraphic and paleobiogeographic implications
a Departamento de Paleontología, Instituto de Geología (UNAM), Ciudad Universitaria, México, D.F. Coyoacán, 04510 Mexico b Department of Paleontology, Hungarian Natural History Museum, Budapest 1431 Pf. 137, Hungary