Aetiocetidae

Aetiocetidae
Temporal range: Oligocene
Aetiocetus cotylalveus, an early baleen whale from the Late Oligocene of Oregon, pencil drawing, digital coloring
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Superfamily: †Aetiocetoidea
Family: †Aetiocetidae
Emlong, 1966[1]
Genera[2]

Aetiocetidae is an extinct family of toothed baleen whales known from the Oligocene and latest Eocene, so far only from rocks deposited in the North Pacific Ocean.[3][2][4] The whales ranged in size from 3 to 8 metres (10 to 26 ft) long. Many of the described specimens were discovered from the Upper Oligocene of the Japanese Morawan Formation, the largest known one from the Morawan's Upper tuffaceous siltstone. Other formally described extinct toothed mysticetis from this time are smaller, from 3 to 4 metres (10 to 13 ft) in length. Mysticeti with true baleen are seen in fossils from the Upper Oligocene. The monophyly of the family is still uncertain, as are the evolutionary relationship between the early toothed baleen whales (Aetiocetidae, Mammalodontidae, and Llanocetidae) and the early and extant edentulous baleen whales.[5] However, the cladistic analyses of Coronodon and Mystacodon seem to indicate that Aetiocetidae and Llanocetidae are more closely related to crown Mysticeti than to Mammalodontidae, Coronodon, and Mystacodon.[6][7]

  1. ^ Marx, Felix G.; Tsai, Cheng-Hsiu; Fordyce, R. Ewan (2 December 2015). "A new Early Oligocene toothed 'baleen' whale (Mysticeti: Aetiocetidae) from western North America: one of the oldest and the smallest". Royal Society Open Science. 2 (12): 150476. doi:10.1098/rsos.150476. PMC 4807455. PMID 27019734.
  2. ^ a b Tsai, Cheng-Hsiu; Ando, Tatsuro (14 April 2015). "Niche Partitioning in Oligocene Toothed Mysticetes (Mysticeti: Aetiocetidae)". Journal of Mammalian Evolution. 23: 33–41. doi:10.1007/s10914-015-9292-y.
  3. ^ Prothero, Donald R.; Berggren, William A., eds. (2014). "18 Cetacean Evolution and Eocene/Oligocene Environments". Eocene-Oligocene Climatic and Biotic Evolution. Princeton University Press. p. 371. ISBN 9780691604954.
  4. ^ Tsai, C.-H., Goedert, J.L., and Boessenecker, R.W. 2024. The oldest mysticete in the Northern Hemisphere. Current Biology 34:P1794-1800.E3. https://doi.org/10.1016/j.cub.2024.03.11
  5. ^ Marx, Felix G. (25 September 2010). "The More the Merrier? A Large Cladistic Analysis of Mysticetes, and Comments on the Transition from Teeth to Baleen". Journal of Mammalian Evolution. 18 (2): 77–100. doi:10.1007/s10914-010-9148-4.
  6. ^ Lambert, Olivier; Martínez-Cáceres, Manuel; Bianucci, Giovanni; Di Celma, Claudio; Salas-Gismondi, Rodolfo; Steurbaut, Etienne; Urbina, Mario; de Muizon, Christian (2017). "Earliest Mysticete from the Late Eocene of Peru Sheds New Light on the Origin of Baleen Whales". Current Biology. 27: 1535–1541.e2. doi:10.1016/j.cub.2017.04.026. hdl:11581/396095. PMID 28502655.
  7. ^ Geisler, Jonathan H; Boessenecker, Robert W; Brown, Mace; Beatty, Brian L (2017). "The Origin of Filter Feeding in Whales". Current Biology. 27 (13): 2036–2042. doi:10.1016/j.cub.2017.06.003. PMID 28669761.