List of fossil pinnipedimorphs explained

Pinnipeds are marine mammals that evolved from arctoid carnivorans that includes seals, eared seals, and walruses. There are 34 recent species of pinnipeds[1] and 102 species of fossil pinnipeds and their stem-relatives (Pinnipedimorpha), collectively referred to as pinnipedimorphs.[2] Scientists still debate on which lineage of arctoid carnviroans are the closest relatives to the pinnipedimorphs, being either more closely related to bears or to musteloids.[3] [4] [5] [6] [7] Two stem-pinniped families found outside of Pinnipedimorpha, Amphicynodontidae and Semantoridae, were in the past considered to be subfamilies of Ursidae and Mustelidae respectively.[8] In comparison to the two other major groups of marine or sea mammals, cetaceans and sirenians, pinnipeds are a relatively younger group having appeared about 24 to 38 million years ago and are still able to return on land to breed.

The list of fossil taxa is based on mostly the historiographical data from Valenzuela-Toro and Pyenson (2019).[2] The two stem-pinniped arctoid families Amphicynodontidae and Semantoridae are included here as well, although neither family are members of Pinnipedimorpha. The list does not include the recently extinct Caribbean monk seal (Neomonachus tropicalis) and the Japanese sea lion (Zalophus japonicus), as they became extinct within the last two centuries.

Phylogeny

Below is an overall phylogeny of the taxa covered in the article followed after a composite tree in Berta et al. (2018)[8] and a total-evidence (combined molecular-morphological) dataset in Paterson et al. (2020):[9]

Stem-pinniped arctoids

†Amphicynodontidae Simpson, 1945

†Semantoridae Orlov, 1931

Stem-pinniped pinnipedimorphs

†Enaliarctidae Mitchell & Tedford, 1973

Stem-pinniped pinnipediforms

Pinnarctidion Barnes, 1979

Pacificotaria Barnes, 1992

Pteronarctos Barnes, 1989

Pinnipeds

Phocoidea J.E. Gray, 1821

Otarioidea J.E. Gray, 1821

See also

Notes and References

  1. Berta . A. . Churchill . M.. 2012 . Pinniped taxonomy: review of currently recognized species and subspecies, and evidence used for their description. . Mammal Review . 42 . 3 . 207–234 . 10.1111/j.1365-2907.2011.00193.x.
  2. Valenzuela-Toro . A. . Nicholas Pyenson . Pyenson . N. D. . 2019 . What do we know about the fossil record of pinnipeds? A historiographical investigation. . Royal Society Open Science . 6 . 11 . 207–234 . 10.1098/rsos.191394 . 31827869. 6894555 . 2019RSOS....691394V . free .
  3. Lento, G. M. . Hickson, R. E. . Chambers, G. K. . Penny, D. . 1995 . Use of spectral analysis to test hypotheses on the origin of pinnipeds . Molecular Biology and Evolution . 12 . 1 . 28–52 . 7877495 . 10.1093/oxfordjournals.molbev.a040189.
  4. Hunt, R. M. Jr. . Barnes, L. G. . 1994. Basicranial evidence for ursid affinity of the oldest pinnipeds. Proceedings of the San Diego Society of Natural History. 29. 57–67. PDF.
  5. Higdon, J. W. . Bininda-Emonds, O. R. . Beck, R. M. . Ferguson, S. H. . Phylogeny and divergence of the pinnipeds (Carnivora: Mammalia) assessed using a multigene dataset . 10.1186/1471-2148-7-216 . BMC Evolutionary Biology . 7 . 216 . 2007 . 1 . 17996107 . 2245807 . free . 2007BMCEE...7..216H .
  6. Sato, J. J. . Wolsan, M. . Suzuki, H. . Hosoda, T. . Yamaguchi, Y. . Hiyama, K. . Kobayashi, M. . Minami, S. . 10.2108/zsj.23.125 . Evidence from nuclear DNA sequences sheds light on the phylogenetic relationships of Pinnipedia: Single origin with affinity to Musteloidea . Zoological Science . 23 . 2 . 125–46 . 2006 . 16603806. 2115/13508 . 25795496 . free .
  7. Flynn, J. J. . Finarelli, J. A. . Zehr, S. . Hsu, J. . Nedbal, M. A. . Molecular phylogeny of the Carnivora (Mammalia): Assessing the impact of increased sampling on resolving enigmatic relationships . 10.1080/10635150590923326 . Systematic Biology . 54 . 2 . 317–37 . 2005 . 16012099. free .
  8. Berta, A. . Churchill, M. . Boessenecker, R.W. . amp . 2018 . The Origin and Evolutionary Biology of Pinnipeds: Seals, Sea Lions, and Walruses . Annual Review of Earth and Planetary Sciences . 46 . 203–228 . 10.1146/annurev-earth-082517-010009. 2018AREPS..46..203B . free .
  9. Paterson . R. S. . Rybczynski . N.. Kohno . N.. Maddin . H. C. . 2020 . Pinniped taxonomy: review of currently recognized species and subspecies, and evidence used for their description. . Frontiers in Ecology and Evolution . 7 . 457 . 10.3389/fevo.2019.00457. free .
  10. Jacob N. Biewer . Jorge Velez-Juarbe . James F. Parham . 2020 . Insights on the dental evolution of walruses based on new fossil specimens from California . Journal of Vertebrate Paleontology . 40 . 5 . e1833896 . 10.1080/02724634.2020.1833896 . 2020JVPal..40E3896B .