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Miophyseter
''Miophyseter'' is an extinct genus of sperm whale in the superfamily Physeteroidea. It includes only one species, ''M. chitaensis'', that was described in 2022 from the lower Miocene (Burdigalian) of Toyohama Formation, Chita District, Aichi Prefecture, Japan. This species is known from the well-preserved cranium with detached teeth and ear bones (Periotic bone, periotic, tympanic bulla, and malleus). ''Miophyseter'' is part of the Physeteroidea stem group, but more closely related to the crown group than to the macroraptorial sperm whales known from middle and late Miocene. ''Miophyster'' may have had an adaptation to deep diving and / or developed pterygoid muscle (other), pterygoid muscles for active biting. The researchers made this conclusion judging by the presence of a deep and large notch on the ventral surface of the palatine bone and pterygoid bone, pterygoid. References Miocene cetaceans Miocene mammals of Asia Prehistoric toothed whales Physeteroid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physeteroidea
Physeteroidea is a superfamily that includes three extant species of whales: the sperm whale, in the genus ''Physeter'', and the pygmy sperm whale and dwarf sperm whale, in the genus ''Kogia''. In the past, these genera have sometimes been united in a single family, the Physeteridae, with the two ''Kogia'' species in the subfamily Kogiinae; however, recent practice is to allocate the genus ''Kogia'' to its own family, the Kogiidae, leaving the Physeteridae as a monotypic (single extant species) family, although additional fossil representatives of both families are known. Characteristics The sperm whale (''Physeter macrocephalus'') is the largest species of toothed whale, with adult bulls (males) growing to be about long, and weighing about . The two kogiid species are much smaller, around in length, and weighing . The bodies of physeteroids are robustly proportioned, with paddle-shaped flippers. The lower jaw is always relatively small and thin relative to the upper jaw. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
