Genus: Ankylosphenodon REYNOSO, 2000
Etymology: Greek, ankylos and sphenodon; in reference to the teeth ankylosed into the lower jaw, and to Sphenodon, the only surviving genus of the Sphenodontia.

Species: pachyostosus REYNOSO, 2000

Holotype: IGM 7441

Locality: Tlayua Quarry, 2 km southeast of the Colonia Morelos, near Tepexi de Rodriguez, Puebla State, Mexico.

Horizon: Middle member of the Tlayua Formation.


Age: Middle or Late Albian Stage, Middle Gallic Subepoch, Uppermost Early Cretaceous Epoch, Early Cretaceous.

Material: Fragmentary skull and fragmentary skeleton.

Referred material:

IGM 7443, 7442, 7445: Fragmentary skull and fragmentary skeleton.

IGM 7446, 7447: Fragmentary skeletons.

Note: Aquatic.