Genus: Alegeinosaurus CASE, 1911
Etymology:

Species: aphthitos (CASE, 1907) CASE, 1911
Etymology:
= Zatrachys apicalis CASE, 1907 (partim)

Holotype: AMNH 4556

Locality: Coffee Creek, Willbarger County, Texas.

Horizon: Arroyo Formation, Lower Clear Fork Group.

Biostratigraphy: Land-vertebrate faunachron lower D.

Age: Middle Leonardian stage, upper Rotliegendes, Early Permian.

Material: Partial anterior axial and appendicular skeleton, including several articulated segments of dorsal dermal armor.