Cetotherium

Cetotherium Temporal range: Miocene–Pliocene PreЄ Є O S D C P T J K Pg N
Mounted skeleton of Cetotherium riabinini
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Cetacea
Suborder:	Mysticeti
Family:	Cetotheriidae Brandt 1872
Genus:	Cetotherium Brandt 1843
Species[1]
†C. crassangulum Cope 1895 †C. furlongi Kellogg 1925 †C. incertum Brandt 1873 †C. priscum Eichwald 1840 †C. pusillum Nordmann 1860 †C. rathkii Brandt 1843 (type) †C. riabinini Hofstein 1948

Cetotherium ("whale beast") is a genus of cetaceans from the family Cetotheriidae.^[2]

Taxonomy

C. riabinini skull

The family Cetotheriidae and the genus Cetotherium (sensu lato) have been used as wastebaskets for all kinds of baleen whales, most notably by Brandt 1873, Spassky (1954) and Mčedlidze 1970. Based on more recent phylogenetic studies and revisions of many 19th century genera, much smaller monophyletic Cetotheriidae and Cetotherium sensu stricto is limited to a single or only a few species. For example, Gol'din, Startsev & Krakhmalnaya 2013 included only C. rathkii and C. riabinini in the genus and only ten genera in the family.^[3]

Cetotheriidae were thought to have gone extinct during the Pliocene until 2012, when it was hypothesized that the Pygmy right whale was the sole surviving species of this family.^[4]

Formerly assigned to Cetotherium

The following species were originally described as nominal species of Cetotherium but have been either reassigned to other genera or removed from Cetotherium:

• Cetotherium furlongi Kellogg, 1925,^[5] is known from a partial skull from the Burdigalian of the Vaqueros Formation in California, but the holotype is lost.^[6]
• Cetotherium gastaldii Strobel, 1875,^[7] known from the early Pliocene-age Sabbie d'Asti Formation of the Piedmont region in Italy, is now the type species of the eschrichtiid genus Eschrichtioides.^[8]
• Cetotherium klinderi Brandt, 1871,^[9] is known from an isolated earbone from Miocene sediments in Chişinău, Moldova. Although fragmentary, it does not appear to be congeneric with either of the two valid species of Cetotherium.^[3]
• Cetotherium maicopicum Spasski, 1951,^[10] based on a specimen from the late Miocene of the Russian Caucasus, has been reassigned to the genus Kurdalagonus from the same region.^[11]
• Cetotherium mayeri Brandt, 1871,^[9] known from a partial skeleton, is apparently not congeneric with Cetotherium.^[3]

Evolution

Restoration of C. furlongi

Cetotheres came into existence during the Oligocene epoch. The cetotheres have been divided into two sub-groups. One group includes Cetotherium. From evolutionary perspective, these whales share some characteristics of the Balaenopteridae and Eschrichtiidae.^[12]

Paleobiology

Fossil record have revealed predator-prey relationship between large sharks (e.g. C. megalodon) and Cetotheriids. The raptorial toothed whale, Livyatan melvillei, may too have posed a threat to these whales.

See also

• Evolution of Cetaceans

References

Notes

1. "Classification of the family Cetotheriidae". Fossilwork. Retrieved December 2013.
2. Berta & Deméré 2008
3. Gol'din, Startsev & Krakhmalnaya 2013, pp. 2, 4–6
4. Fordyce, R. E.; Marx, F. G. (2013). "The pygmy right whale Caperea marginata: the last of the cetotheres". Proceedings of the Royal Society B: Biological Sciences 280 (1753): 1–6. doi:10.1098/rspb.2012.2645.
5. R. Kellogg. 1925. Fossil cetotheres from California. Contributions to Palaeontology from the Carnegie Institution of Washington 348(2):35-56
6. Kimura, T.; Hasegawa, Y. (2010). "A new baleen whale (Mysticeti: Cetotheriidae) from the earliest Late Miocene of Japan and a reconsideration of the phylogeny of Cetotheres". Journal of Vertebrate Paleontology 30 (2): 577–591. doi:10.1080/02724631003621912.
7. Strobel, P. (1875). "Notizie preliminari su le Balenoptere fossili subappennine del Museo parmense". Bollettino del R. Comitato Geologico d'Italia (in Italian) 5 (6): 131–140. Retrieved November 2013. Lay summary (November 2013).
8. Bisconti, M. (2008). "Morphology and phylogenetic relationships of a new eschrichtiid genus (Cetacea: Mysticeti) from the Early Pliocene of northern Italy". Zoological Journal of the Linnean Society 153: 161–186. doi:10.1111/j.1096-3642.2008.00374.x. OCLC 438026086. Lay summary (November 2013).
9. Brandt, J. F. 1871. Bericht uber den Fortgang meiner Studien uber di Cetaceen, welche das grosse zur Tertiarzeit von Mitteleuropa bis Centralasien hinein ausgedehnte Meeresbechen bevolkerten. Bulletin de l'Academie Imperiale de St. Petersbourg 16: 563–566.
10. P. I. Spasski. 1951. Ostaki tsetoheriev iz Servernogo Kavkaza (okr. g. Maikopa) Remains of cetotheria from the Northern Caucasus in the neighborhood of Maikop Town. Izvestia Akademii Nauk Azerbaidzhanskoi SSR 2:57-65
11. K. K. Tarasenko and A. V. Lopatin. 2012. New Baleen Whale Genera (Cetacea, Mammalia) from the Miocene of the Northern Caucasus and Ciscaucasia: 1. Kurdalagonus gen. nov. from the Middle–Late Sarmatian of Adygea. Paleontological Journal 46(5):531-542
12. Kimura & Ozawa 2002

Sources

• Barry Cox, Colin Harrison, R.J.G. Savage, and Brian Gardiner. (1999): The Simon & Schuster Encyclopedia of Dinosaurs and Prehistoric Creatures: A Visual Who's Who of Prehistoric Life. Simon & Schuster.
• Berta, Annalisa; Deméré, Thomas (2008). "Mysticetes, Evolution" (PDF). In Perrin, William F.; Würsig, Bernd; Thewissen, J. G. M. Encyclopedia of Marine Mammals. Academic Press. pp. 751–752. ISBN 978-0-12-373553-9.
• Brandt, J. F. (1843). "De Cetotherio, novo Balaenarum familiae genere in Rossia meridionali ante aliquot annos effesso". Bulletin de la classe physico-mathématique de l'Académie impériale des sciences de Saint-Pétersbourg (in French) 1 (10–12). Retrieved November 2013. Lay summary (November 2013).
• Brandt, J. F. (1872). "Über eine neue Classification der Bartenwhale (Balaenoidea) mit Berücksichtigung der untergegangenen Gattungen derselben". Bulletin de L'Académie imperiale des sciences de St.-Pétersbourg. 3 (in German) 17. Retrieved November 2013. Lay summary (November 2013).
• Brandt, J. F. (1873). "Untersuchungen über die fossilen und subfossilen Cetaceen Europa's". Mémoires de L'Académie Impériale des Sciences de Saint-Petersbourg. 7 20 (1): 1–372. Retrieved December 2013. Lay summary (December 2013).
• Gol'din, P.; Startsev, D.; Krakhmalnaya, T. (2013). "The anatomy of Cetotherium riabinini Hofstein, 1948, a baleen whale from the late Miocene of Ukraine". Acta Palaeontologica Polonica. In press. doi:10.4202/app.2012.0107.
• Kimura, Toshiyuki; Ozawa, Tomowo (2002). "New Cetothere (Cetacea: Mysticeti) from the Miocene Chichibumachi Group, Japan.". Bulletin of the Saitama Museum of Natural History 22 (3): 684–702. JSTOR 4524259.
• Mčedlidze, G. A. (1970). Some General Characteristics of the Evolution of Cetaceans, Part 1 (PDF) (in Russian and English). Translated by Dorothy B. Vitaliano. Tbilisi: Akademia Nauk Gruzinskoi S.S.R. Institut Paleobiologii. OCLC 663053619. Retrieved December 2013. Lay summary (December 2013).