Pinnipeds are
marine mammals that evolved from
arctoidcarnivorans 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.[9] 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]
^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.
doi:
10.1111/j.1365-2907.2011.00193.x.
^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.
doi:
10.1093/oxfordjournals.molbev.a040189.
PMID7877495.
^Sato, J. J.; Wolsan, M.; Suzuki, H.; Hosoda, T.; Yamaguchi, Y.; Hiyama, K.; Kobayashi, M.; Minami, S. (2006). "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.
doi:
10.2108/zsj.23.125.
hdl:2115/13508.
PMID16603806.
S2CID25795496.
^
abcJacob 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.
doi:
10.1080/02724634.2020.1833896.
Pinnipeds are
marine mammals that evolved from
arctoidcarnivorans 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.[9] 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]
^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.
doi:
10.1111/j.1365-2907.2011.00193.x.
^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.
doi:
10.1093/oxfordjournals.molbev.a040189.
PMID7877495.
^Sato, J. J.; Wolsan, M.; Suzuki, H.; Hosoda, T.; Yamaguchi, Y.; Hiyama, K.; Kobayashi, M.; Minami, S. (2006). "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.
doi:
10.2108/zsj.23.125.
hdl:2115/13508.
PMID16603806.
S2CID25795496.
^
abcJacob 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.
doi:
10.1080/02724634.2020.1833896.