''Morawanocetus'' is a genus of extinct primitive

baleen whale Baleen whales (), also known as whalebone whales, are marine mammals of the order (biology), parvorder Mysticeti in the infraorder Cetacea (whales, dolphins and porpoises), which use baleen plates (or "whalebone") in their mouths to sieve plankt ...

from the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Aetiocetidae Aetiocetidae is an extinct Family (biology), family of toothed Baleen whale, baleen whales known from the Oligocene and latest Eocene, so far only from rocks deposited in the North Pacific Ocean. The whales ranged in size from long. Many of the ...

that existed during the

Chattian The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...

stage of the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

epoch. Its fossils have been found in the

North Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the contine ...

. ''Morawanocetus'' was named by Barnes ''et al.'' in 1995, who described the species, ''M. yabukii''. Three new species, dating from 17 to 19 million years ago, were unearthed between 2000 and 2005 in a road-widening project in California. These three new specimens of ''Morawanocetus'', a genus thought to have gone extinct some five million years earlier, were discovered next to a fourth specimen, still under preparation, which clearly has archaeocete dentition.. CSUF. Retrieved 11 January 2014. ''Morawanocetus'' was divergent, with wide crania, elaborate cheek, tooth crowns, and short necks. The first fossils of ''Morawanocetus'' were found in the

-aged Morawan Formation of Upper Oligocene

Hokkaido is the list of islands of Japan by area, second-largest island of Japan and comprises the largest and northernmost prefectures of Japan, prefecture, making up its own list of regions of Japan, region. The Tsugaru Strait separates Hokkaidō fr ...

. The more recent findings are the first ''Morawanocetus'' fossils found in California, a genus more commonly known to Japan. ''Morawanocetus'' is a sister taxa to: ''

Aetiocetus ''Aetiocetus'' is a genus of extinct basal mysticete, or baleen whale that lived , in the Oligocene in the North Pacific ocean, around Japan, Mexico, and Oregon, U.S. It was first described by Douglas Emlong in 1966 and currently contains kno ...

'', ''

Ashorocetus ''Ashorocetus'' is a monotypic genus of an extinct primitive baleen whale of the family Aetiocetidae. It was named by , and contains one species, ''A. eguchii''. Fossils of this whale are found from the Chattian Morawan formation, near Ashoro ...

'', '' Chonecetus'', and '' Willungacetus''.

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* ** Oligocene mammals of Asia Oligocene mammals of North America Oligocene cetaceans Extinct animals of Japan Aetiocetidae Prehistoric cetacean genera Fossil taxa described in 1995 {{Paleo-whale-stub