Genus: Plesiosaurus non CONYBEARE, 1821
Species: (Polyptychodon) mexicanus WIELAND,
1910 (nomen dubium)
Etymology:
Holotype: UNAM IGM 9026
Locality: At a point north of Putla, 6 km south-southwest of Tlaxiaco, Mixteca, Oaxaca State, Southern most Mexico.
Horizon:
Biostratigraphy:
Age: Neocomian Subepoch, Early Cretaceous Subepoch, Early Cretaceous.
Material: Part of side of skull containing 5 upper and 5 lower teeth.
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