Diaphorocetus

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.
Systematics.
"Diaphorocetus" was originally named "Mesocetus" by Moreno (1892). Lydekker (1893) found that "Mesocetus" was already in use for an extinct mysticete, so he renamed the sperm whale "Hypocetus". Ameghino (1894) too recognized Moreno's name as preoccupied, but unaware of Lydekker's paper, coined his own replacement name "Diaphorocetus" for "Mesocetus". "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.
Paleoecology.
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.