Zygophyseter

Zygophyseter varolai is a cetacean that lived during the Tortonian Age of the Late Miocene 11.2 to 7.6 million years ago, and was similar to the modern day sperm whale (Physeter macrocephalus). It is known from a single specimen from the Pietra Leccese Formation in Italy. It was a member of a stem group of fossil macroraptorial sperm whales (often shortened to "raptorial") Brygmophyseter, Acrophyseter, and Livyatan. It grew to be around 6.5 to 7 meters (21 to 23 ft) in length and shared some characteristics with other raptorials, such as large teeth with tooth enamel that were functional in both the upper and lower jaws. It also had a beak, the ability to echolocate prey, and could have probably swum faster than the modern day sperm whale which goes 4 kilometers per hour (2.5 mph). These were probably used in the capture of large prey, such as large fish, seals, and whales. In fact, its common name, killer sperm whale, refers to its feeding habits that would have had a resemblance to the modern day killer whale (Orcinus orca).