|
| Blanco-Piñón, Alberto, Garibay-Romero, Luis M. and Alvarado-Ortega, Jesús The oldest stratigraphic record of the Late Cretaceous shark Ptychodus mortoni Agassiz, from Vallecillo, Nuevo León, northeastern Mexico. Rev. mex. cienc. geol, Apr 2007, vol.24, no.1, p.25-30. ISSN 1026-8774
|
|