Hoplocetus

Hoplocetus
Temporal range: Middle Miocene-Early Pleistocene
~16.0–1.8 Ma [1]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Superfamily: Physeteroidea
Family: incertae sedis
Genus: †Hoplocetus
Gervais, 1852
Species
  • H. borgerhoutensis du Bus, 1872
  • H. crassidens Gervais, 1852 (type)
  • H. curvidens Gervais, 1852
  • H. obesus Leidy, 1868[2]
  • H. ritzi Hampe, 2006[3]

Hoplocetus is an extinct genus of raptorial cetacean of the sperm whale superfamily, Physeteroidea.[3] Its remains have been found in the Miocene of Belgium, France, Germany and Malta, the Pliocene of Belgium and France, and the Pleistocene of the United Kingdom and South Carolina.[1]

Dentition

The teeth of Hoplocetus are massive (95–150 mm in length; 27–47 in maximum diameter), robust and have a short enamel cap on the crowns.[3] They are somewhat larger than those of modern orcas[4] but considerably smaller than those of macroraptorial sperm whales, such as Zygophyseter, as well as those of Scaldicetus caretti.[5] They display a large degree of abrasion, suggesting a highly predatory niche comparable to that of modern orcas.[3] The genus of the latter, Orcinus, first appears in the middle Pliocene and it may have eventually replaced Hoplocetus.[3]

These teeth features also characterize the other extinct toothed whale genera, Diaphorocetus, Idiorophus and Scaldicetus, sometimes placed with Hoplocetus in the subfamily Hoplocetinae.[6] However, some of these taxa are fragmentary and have been used as wastebasket taxa for non-diagnostic material of stem physeteroids.

References

  1. ^ a b "Hoplocetus in the Paleobiology Database". Fossilworks. Archived from the original on 12 December 2021. Retrieved 17 December 2021.
  2. ^ Leidy, J. (1868). "Notice of Some Extinct Cetaceans". Proceedings of the Academy of Natural Sciences of Philadelphia. 20: 196–197. Retrieved 2018-11-12.
  3. ^ a b c d e Hampe, O. (2006). "Middle/late Miocene hoplocetine sperm whale remains (Odontoceti: Physeteridae) of North Germany with an emended classification of the Hoplocetinae". Fossil Record. 9 (1): 61–86. doi:10.1002/mmng.200600002.
  4. ^ Bradford, A. (2014-11-20). "Orcas: Facts About Killer Whales". Live Science. Retrieved 2018-11-12.
  5. ^ Reumer, J. W. F.; Mens, T. H.; Post, K. (2017). "New Finds of Giant Raptorial Sperm Whale Teeth (Cetacea, Physeteroidea) from the Westerschelde Estuary (Province of Zeeland, the Netherlands)" (PDF). Deinsea. 17: 32–38. Retrieved 2018-11-12.
  6. ^ Toscano, A.; Abad, M.; Ruiz, F.; Muñiz, F.; Álvarez, G.; García, E.; Caro, J. A. (2013). "Nuevos Restos de Scaldicetus (Cetacea, Odontoceti, Physeteridae) del Mioceno Superior, Sector Occidental de la Cuenca del Guadalquivir (Sur de España)" [New Remains of Scaldicetus (Cetacea, Odontoceti, Physeteridae) from the Upper Miocene, Western Sector of the Guadalquivir Basin]. Revista Mexicana de Ciencias Geológicas (in Spanish). 30 (2).