Macroraptorial sperm whale

The term "macroraptorial" combines the Greek prefix "macro-" ("long", "large" or "great") and "raptorial" (from Latin rapere meaning "to seize", "to grasp"). ==Discovery==

Zygophyseter was discovered in the Pietra Leccese Formation in Italy from a skull, teeth, and vertebrae; Brygmophyseter was discovered in the Bessho Formation in Japan from a nearly-complete skeleton; Albicetus was discovered at the Santa Barbara Lighthouse in 1909, in what is believed to most likely be part of the Monterey Formation. It was first classified within the genus Ontocetus (now a genus of walrus), and then moved to a wastebasket taxon Scaldicetus until Boersma and his colleagues assigned a new generic name. ==Description==

Macroraptorial sperm whales had large, functional, conical teeth in both jaws, as opposed to the modern sperm whale whose teeth are small and nonfunctional in the upper jaw. The teeth were deeply rooted into the gumline and could interlock, probably to aid in holding struggling prey. The teeth of Livyatan, at a length of , were one of the biggest teeth of any animal, excluding tusks. The macroraptorials also had well-developed muscles used in biting—the temporalis and masseter. They also developed buccal exostoses in the mouth, bony growths which act as buttresses during biting, further increasing the bite force. Like modern sperm whales, the macroraptorials had a curved basin—the supracranial basin—on the top of the skull. This encompassed the entire breadth of the snout in Livyatan and Brygmophyseter; ==Paleobiology==

as killer whales (Orcinus orca). Using their large and deeply rooted teeth, wide-opening jaws, and great size, they likely fed on a variety of sea life, including fish, cephalopods, seals, and small whales and dolphins, occupying a niche similar to the modern day killer whale (Orcinus orca). In sperm whales, the supracranial basin holds the spermaceti organ, a series of oil and wax reservoirs which aids in echolocation. Speculatively, the organ may also serve a secondary function, such as vocalizing, acoustic stunning of prey, head-butting between males, ramming into prey, or buoyancy control by increasing or decreasing the temperature of the wax to change the density and weight. ==Taxonomy==

The macroraptorial sperm whales are a paraphyletic fossil group of hyper-predatory stem sperm whales. All share large, functional, enamel-coated teeth on both the upper and lower jaws, which were used in capturing large prey. In contrast, the modern sperm whale (Physeter macrocephalus) lacks enamel, teeth in the upper jaw, and the ability to use its teeth to catch prey. It has also been suggested that the macroraptorials be placed into the subfamily Hoplocetinae, a subfamily characterized by robust and enamel-coated teeth, alongside the genera Diaphorocetus, Idiorophus, and Hoplocetus, which are known from the Miocene to the Early Pleistocene. However, most of these whales are known from fragmentary remains or have been used as wastebasket taxa for indiscernible stem sperm whale remains. }} }} ==See also==