Messapicetus
Messapicetus is an extinct genus of beaked whale from the Late Miocene. It currently holds two species, "M. longirostris" from the Tortonian of Italy and "M. gregarius" from the Pisco Formation of Peru. However, a third unnamed species is represented in the St. Marys Formation of Maryland known from fragmentary material. "M. gregarius" is sexually dimorphic, males having tusks which are hypothesized to have been used in intraspecific combat for mates as in extant (living) beaked whales.