D. poucheti (type) Diaphorocetus is an extinct genus of odontocete cetacean belonging to Physeteroidea.

Its remains were found in the Monte León Formation of Argentina, dating to the Early Miocene.

[2] Lydekker (1893) found that Mesocetus was already in use for an extinct mysticete, so he renamed the sperm whale Hypocetus.

[4] Diaphorocetus was declared a nomen protectum (protected name) by Paolucci et al. (2019) because Hypocetus and Paracetus have not been used as valid since 1899 under Article 23.9 of the Code.

[5] The small teeth of Diaphorocetus and the bottleneck-like nature of the rostrum suggest that Diaphorocetus employed a feeding strategy intermediate between that of raptorial sperm whales like Acrophyseter and Livyatan and extant sperm whales.