Genus: Tenontosaurus OSTROM, 1970
Etymology: Greek, tenon (masculine),"sinew," in reference to ossified tendons along the vertebral column, and Greek, sauros (masculine), lizard.

Species: tillettorum OSTROM, 1970
Etymology: Named for the Lloyd Tillett family of Lovell, Wyoming, to whom we are indebted for assistance and hospitality extended to our field parties.

Referred material:

NUDDS, LOMAX & TENNANT, 2022

Locality: Private land, The Kelly Ranch, Weatland County, Montana.

Horizon: Cloverly Formation.

Biostratigraphy:

Age: Cashenranchian, Late Aptian-Early Albian Stage, middle Gallic subepoch, lower Cretaceous Epoch, Early Cretaceous.

Material:

MANCH LL12275: Semi-complete skull, complete vertebral column (atlas, axis, cervical, dorsal, sacral and caudal series) minus most caudal neural spiens, paired scapulae, coracoids and sternal plates, humeri, ulnae and radii, near complete manus with carpus, ilia, sichia, pubes, femora, fibulae, and tibiae, tarsus and pes complete.

Note: Found with 12 gastroliths and 2 fragmentary Deinonychus antirrhopus teeth.