Comments on "The oldest stratigraphic record of the Late Cretaceous shark Ptychodus mortoni Agassiz, from Vallecillo, Nuevo León, northeastern Mexico'' by Blanco-Piñón et al., Rev. Mex. Cienc. Geol. (2007), 24, 25-30 Revista Mexicana de Ciencias Geológicas, 25(2), 365–366
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Late Cretaceous (Turonian) fish assemblage from Vallecillo, Northeastern Mexico. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 225(1), 39–54