Species: texensis WILLISTON, 1914
Etymology:
Holotype: FMNH (CNHM) UC684
Locality: Mitchell Creek, Archer County, Texas.
Horizon: Clyde Formation, Clear Fork Group.
Biostratigraphy:
Age: Leonardian, Hessian, Lower Artinskian Stage, Lower Rotliegendes Epoch, Early Permian.
Material: Skull, dorsal armor and miscellaneous limb bones.
Referred material:
FMNH (CNHM) UC 685: Skull, dorsal armor and miscellaneous limb bones.
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Species: brevis CARROLL, 1964
Etymology:
Holotype: MCZ 1424
Locality: Archer City bone bed, 1 mile southwest of Archer City, Archer County, Texas.
Horizon: Archer City Formation (formerly Putnam Formation), Wichita Group.
Biostratigraphy:
Age: Leonardian series, Upper Rotilegendes Epoch, Early Permian.
Material: Skull and lower jaw with 12 vertebrae, 9 armor plates, 9 ribs, left
and right cleithra and scapulae, fragments of the clavicles and left humerus.
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Species: arroyoensis DEMAR, 1967
Etymology:
Holotype: FMNH UR431
Locality: East Coffee Creek, Baylor County, Texas.
Horizon: Arroyo Formation, Clear Fork Group.
Biostratigraphy:
Age: Artinskian Stage, Lower Rotliegendes Epoch, Early Permian.
Material: Anterior two-thirds of a skull, including the entire skull roof to a point just posterior to the orbits, and the complete upper and lower jaws to the articulation on the right side.
Referred material:
FMNH UR810: A nearly complete armor carapace.
FMNH UR812: Part of the shoulder girdle and carapace.