Species: annectens BOLT, 1974
Etymology: Latin, annectens, "liking or joining."
Holotype: FMNH UR 1308
Locality: Fort Sill, OMNH Locality V51, Dolese Brothers limestone quarry at Richards Spur, Fissure Fills, just west of U.S. Highways 62 & 281, 10.5 miles south of Apache, 6 miles north of Fort Sill, SW 1/2, Sec. 31, T4N, R11W, Comanche County, Oklahoma.
Horizon: Wellington Formation (Garber Formation), Summer Group, Arbuckle limestone, (Probably equivalent to the Arroyo Formation of Texas).
Age: Leonardian Stage, Lower Rotliegendes Epoch, Early Permian.
Material: Nearly complete skull with the dorsal and laterial surfaces exposed, with anterior part of vertebral column and partial right forelimb.
FMNH UR 1323: Fragmentary skull.
FMNH UR 1332: Fragmentary skeleton.
FMNH 5254: Tooth.
FMNH UR 1296, 1307, 1323, plus at least 30 each of uncatalogued prefrontals, palatines, lacrimals, and vomers.