Supayacetus is an extinct genus of basilosaurid cetacean from Middle Eocene (Bartonian stage) deposits of southern Peru.
Supayacetus is known from the holotype MUSM 1465, a partial skeleton. As Ocucajea, it was collected in the Archaeocete Valley site, from the Paracas Formation of the Pisco Basin about 40.4 to 37.2 million years ago.[2] It was named by Uhen et al. 2011 and the type species S. muizoni honours palaeontologist Christian de Muizon who has contributed considerably to Peruvian palaeontology.[3]
Distinguishing characters of Supayacetus include: a T-shaped manubrium with a rod-shaped process; cheek teeth with accessory denticles; a broad scapula with a large infraspinous fossa; humerus with large and hemispherical head, well-defined proximal tuberosities, a long deltopectoral crest, and a broad shaft. Compared to other basilosaurids, Supayacetus is larger than Protocetus but its skull and vertebrae are smaller than in other basilosaurids.[4]