1. Phylogeny

Below is an overall phylogeny of the taxa covered in the article followed after a composite tree in Berta et al. (2018)^[1] and a total-evidence (combined molecular-morphological) dataset in Paterson et al. (2020):^[2]

2. Stem-Pinniped Arctoids

2.1. Amphicynodontidae Simpson, 1945.

Artist's restoration of Kolponomos newportensis. https://handwiki.org/wiki/index.php?curid=1600997

• †Amphicticeps Matthew & Granger, 1924
  • †Amphicticeps makhchinus Wang et al., 2005
  • †Amphicticeps dorog Wang et al., 2005
  • †Amphicticeps shackelfordi Matthew & Granger, 1924
• †Drassonax Galbreath, 1953
  • †Drassonax harpagops Galbreath, 1953
• †Parictis Scott, 1893 [Campylocynodon Chaffee, 1954]
  • †Parictis primaevus Scott, 1893
  • †Parictis personi (Chaffee, 1954) [Campylocynodon personi Chaffee, 1954]
  • †Parictis montanus Clark & Guensburg, 1972
  • †Parictis parvus Clark & Beerbower, 1967
  • †Parictis gilpini Clark & Guensburg, 1972
  • †Parictis dakotensis Clark, 1936
• †Kolponomos Stirton, 1960
  • †Kolponomos newportensis Tedford et al., 1994
  • †Kolponomos clallamensis Stirton, 1960
• †Allocyon Merriam, 1930
  • †Allocyon loganensis Merriam, 1930
• †Wangictis L. de Bonis et al., 2019
  • †Wangictis tedfordi (Wang & Qiu, 2003) [Pachycynodon tedfordi Wang & Qiu, 2003]
• †Pachycynodon Schlosser, 1888
  • †Pachycynodon tenuis Teilhard de Chardin, 1915
  • †Pachycynodon filholi Schlosser, 1888
  • †Pachycynodon boriei (Filhol, 1876) [Cynodon robustus Filhol, 1876; Pachycynodon gryei (Filhol, 1876); Pachycynodon leymeriei (Filhol, 1876); Pachycynodon curvirostris (Filhol, 1876); Pachycynodon ferratus (Quenstedt, 1885)]
  • †Pachycynodon crassirostris Schlosser, 1888
• †Amphicynodon Filhol, 1881 [Cynodon Aymard, 1848, name already taken by a fish]
  • †Amphicynodon mongoliensis Janovskaja, 1970
  • †Amphicynodon teilhardi (Matthew & Granger, 1924) [Cynodon teilhardi Matthew & Granger, 1924]
  • †Amphicynodon typicus Schlosser, 1888
  • †Amphicynodon chardini Cirot & De Bonis, 1992
  • †Amphicynodon cephalogalinus Teilhard, 1915
  • †Amphicynodon gracilis (Filhol, 1874) [Cynodon gracilis Filhol, 1874]
  • †Amphicynodon crassirostris (Filhol, 1876) [Cynodon crassirostris Filhol, 1874]
  • †Amphicynodon brachyrostris (Filhol, 1876) [Cynodon brachyrostris Filhol, 1876]
  • †Amphicynodon leptorhynchus (Filhol, 1874) [Cynodon leptorhynchus Filhol, 1874]
  • †Amphicynodon velaunus (Aymard, 1846)

2.2. †Semantoridae Orlov, 1931

A restored skeleton of the semantorid Puijila darwini. https://handwiki.org/wiki/index.php?curid=1598444

• †Necromites V. V. Bogachev, 1940
  • †Necromites nestoris V. V. Bogachev, 1940
• †Potamotherium Geoffroy, 1833
  • †Potamotherium miocenicum Peters, 1868
  • †Potamotherium valletoni Geoffroy, 1833
• †Puijila Rybczynski et al., 2009
  • †Puijila darwini Rybczynski et al., 2009
• †Semantor Orlov, 1931
  • †Semantor macrurus Orlov, 1931

3. Stem-pinniped Pinnipedimorphs

3.1. †Enaliarctidae Mitchell & Tedford, 1973

A fossil of Enaliarctos mealsi encased in the matrix.

• †Enaliarctos Mitchell & Tedford, 1973
  • †Enaliarctos barnesi Berta, 1991
  • †Enaliarctos mealsi Mitchell & Tedford, 1973
  • †Enaliarctos tedfordi Berta, 1991
  • †Enaliarctos mitchelli Barnes, 1979
  • †Enaliarctos emlongi Berta, 1991

4. Stem-pinniped Pinnipediforms

4.1. †Pinnarctidion Barnes, 1979

• †Pinnarctidion rayi Berta, 1994
• †Pinnarctidion bishopi Barnes, 1979

4.2. †Pacificotaria Barnes, 1992

• †Pacificotaria hadromma Barnes, 1992

4.3. †Pteronarctos Barnes, 1989

• †Pteronarctos piersoni Barnes, 1990
• †Pteronarctos goedertae Barnes, 1989

5. Pinnipeds

5.1. Phocoidea J. E. Gray, 1821

Skull of Piscophoca pacifica. https://handwiki.org/wiki/index.php?curid=1241148

Skeletal mount of Acrophoca longirostris. https://handwiki.org/wiki/index.php?curid=1712873

• Phocidae J. E. Gray, 1821
  • †Devinophocinae Koretsky & Holec, 2002
    • †Devinophoca Koretsky & Holec, 2002
      • †Devinophoca emryi Koretsky & Rahmat, 2015
      • †Devinophoca claytoni Koretsky & Rahmat, 2002
  • Monachinae E. L. Trouessart, 1897
    • Monachini E. L. Trouessart, 1897
      • †Pristiphoca Gervais, 1853
        • †Pristiphoca rugidens (Meyer, 1845) [Monachus rugidens Meyer, 1845]
        • †Pristiphoca occitana Gervais, 1853
      • †Terranectes Rahmat et al., 2017
        • †Terranectes parvus Rahmat et al., 2017
        • †Terranectes magnus Rahmat et al., 2017
      • †Afrophoca Koretsky & Domning, 2014
        • †Afrophoca libyca Koretsky & Domning, 2014
      • †Noriphoca Dewaele et al., 2018
        • †Noriphoca gaudini Guiscardi, 1870 [Monotherium gaudini Guiscardi, 1870]
      • †Pontophoca Kretzoi, 1941
        • †Pontophoca jutlandica Koretsky et al., 2014
        • †Pontophoca sarmatica (Alekseev, 1924) [Phoca sarmatica Alekseev, 1924]
        • †Pontophoca simionescui Kretzoi, 1941
      • †Palmidophoca Ginsburg & Janvier, 1975
        • †Palmidophoca callirhoe Ginsburg & Janvier, 1975
      • †Messiphoca Muizon, 1981
        • †Messiphoca mauretanica Muizon, 1981
      • †Auroraphoca Dewaele et al., 2018
        • †Auroraphoca atlantica Dewaele et al., 2018
      • †Pliophoca Tavani, 1941
        • †Pliophoca etrusca Tavani, 1941
    • Miroungini Muizon, 1981
      • †Callophoca van Beneden, 1876
        • †Callophoca obscura van Beneden, 1876
    • Lobodontini J. E. Gray, 1869
      • †Australophoca Valenzuela‐Toro et al., 2016
        • †Australophoca Valenzuela‐Toro et al., 2016
      • †Virginiaphoca Dewaele et al., 2018
        • †Virginiaphoca magurai Dewaele et al., 2018
      • †Properiptychus Ameghino, 1897
        • †Properiptychus argentinus Ameghino, 1897
      • †Homiphoca Muizon & Hendey, 1980
        • †Homiphoca capensis (Hendey & Repenning, 1972) [Prionodelphis capensis Hendey & Repenning, 1972]
      • †Piscophoca Muizon, 1981
        • †Piscophoca pacifica Muizon, 1981
      • †Hadrokirus Amson & De Muizon, 2013
        • †Hadrokirus martini Amson & De Muizon, 2013
      • †Acrophoca Muizon, 1981
        • †Acrophoca longirostris Muizon, 1981
  • Phocinae J. E. Gray, 1869
    • †Frisiphoca Dewaele et al., 2018
      • †Frisiphoca affine (van Beneden, 1876) [Monotherium affine van Beneden, 1876]
      • †Frisiphoca aberratum (van Beneden, 1876) [Monotherium aberratum van Beneden, 1876)]
    • †Leptophoca True, 1906
      • †Leptophoca amphiatlantica Koretsky et al., 2012
      • †Leptophoca proxima (van Beneden, 1876) [Phoca proxima van Beneden, 1876; Leptophoca lenis True 1906]
    • †Cryptophoca Koretsky & Ray, 1994
      • †Cryptophoca maeotica (Nordmann, 1860) [Monotherium maeotica Koretsky 2001]
    • †Monotherium van Beneden, 1876
      • †Monotherium delognii van Beneden, 1876
    • †Prophoca van Beneden, 1876
      • †Prophoca rousseaui van Beneden, 1876
    • †Monachopsis Kretzoi, 1941
      • †Monachopsis pontica (Eichwald, 1850) [Monachus pontica Eichwald, 1850]
    • †Sarmatonectes Koretsky, 2001
      • †Sarmatonectes sintsovi Koretsky, 2001
    • †Phocanella van Beneden, 1877
      • †Phocanella pumila van Beneden, 1877
    • †Kawas Cozzuol, 2001
      • †Kawas benegasorum Cozzuol, 2001
    • Erignathini Chapski, 1955
      • †Platyphoca van Beneden, 1876
        • †Platyphoca danica Koretsky et al., 2014
        • †Platyphoca vulgaris van Beneden, 1876
    • Cystophorini Burns & Fay, 1970
      • †Miophoca Zapfe, 1937
        • †Miophoca vetusta Zapfe, 1937
      • †Pachyphoca Koretsky & Rahmat, 2013
        • †Pachyphoca chapskii Koretsky & Rahmat, 2013
        • †Pachyphoca ukrainica Koretsky & Rahmat, 2013
    • Phocini J. E. Gray, 1821
      • †Nanophoca Dewaele et al., 2017
        • †Nanophoca vitulinoides (van Beneden, 1871) [Phoca vitulinoides van Beneden, 1871]
      • Histriophoca Gill, 1873
        • †Histriophoca alekseevi Koretsky, 2001
      • Gryphoca van Beneden, 1877
        • †Gryphoca nordica Koretsky et al., 2014
        • †Gryphoca similis van Beneden, 1877
      • †Batavipusa Koretsky & Peters, 2008
        • †Batavipusa neerlandica Koretsky & Peters, 2008
      • †Praepusa Kretzoi, 1941
        • †Praepusa pannonica Kretzoi, 1941
        • †Praepusa boeska Koretsky et al., 2015
        • †Praepusa magyaricus Koretsky, 2003
        • †Praepusa archankutica Antoniuk & Koretsky, 1984
        • †Praepusa vindobonensis (Toula, 1897) [Phoca vindobonensis Toula, 1897]
      • Phoca Linnaeus, 1758
        • †Phoca moori Newton, 1890

5.2. Otarioidea J. E. Gray, 1821

Skeletal mount of Allodesmus sp. https://handwiki.org/wiki/index.php?curid=1227820

Reconstruction of Archaeodobenus akamatsui by Tatsuya Shinmura (Ashoro Museum of Paleontology). https://handwiki.org/wiki/index.php?curid=1666629

Life restoration of Thalassoleon mexicanus.. https://handwiki.org/wiki/index.php?curid=1652043

• †Desmatophocidae Hay, 1930
  • †Allodesminae Mitchell, 1968
    • †Atopotarus Downs, 1956
      • †Atopotarus courseni Downs, 1956
    • †Allodesmus Kellogg, 1922
      • †Allodesmus packardi Barnes, 1972
      • †Allodesmus uraiporensis Tonomori et al., 2018
      • †Allodesmus naorai Kohno, 1996
      • †Allodesmus sinanoensis Nagao, 1941
      • †Allodesmus demerei Boessenecker & Churchill, 2018
      • †Allodesmus kernensis Kellogg, 1922
  • †Desmatophocinae Hay, 1930
    • †Desmatophoca Condon, 1906
      • †Desmatophoca brachycephala Barnes, 1987
      • †Desmatophoca oregonensis Condon, 1906
• Odobenidae J. A. Allen, 1880
  • †Prototaria Takeyama & Ozawa, 1984
    • †Prototaria planicephala Kohno, 1994
    • †Prototaria primigena Takeyama & Ozawa, 1984
  • †Proneotherium Kohno et al., 1995
    • †Proneotherium repenningi Kohno et al., 1995
  • †Neotherium Kellogg, 1931
    • †Neotherium mirum Kellogg, 1931
  • †Kamtschatarctos Dubrovo, 1981
    • †Kamtschatarctos sinelnikovae Dubrovo, 1981
  • †Pseudotaria Kohno, 2006
    • †Pseudotaria muramotoi Kohno, 2006
  • †Archaeodobenus Tanaka & Kohno, 2015
    • †Archaeodobenus akamatsui Tanaka & Kohno, 2015
  • †Nanodobenus Velez & Salinas-Marquez, 2018
    • †Nanodobenus arandai Velez & Salinas-Marquez, 2018
  • †Pelagiarctos Barnes, 1988
    • †Pelagiarctos thomasi Barnes, 1988
  • †Titanotaria Magallanes et al., 2018
    • †Titanotaria orangensis Magallanes et al., 2018
  • †Imagotaria Mitchell, 1968
    • †Imagotaria downsi Mitchell, 1968
  • †Pontolis True, 1905
    • †Pontolis magnus (True, 1905) [Pontoleon magnus True, 1905]
  • Neodobenia Magallanes et al., 2018
    • †Gomphotaria Barnes & Rashke, 1991
      • †Gomphotaria pugnax Barnes & Rashke, 1991
    • †Dusignathinae Mitchell, 1968
      • †Dusignathus Kellogg, 1927
        • †Dusignathus seftoni Deméré, 1994
        • †Dusignathus santacruzensis Kellogg, 1927
    • Odobeninae J. A. Allen, 1880
      • †Aivukus Repenning & Tedford, 1977
        • †Aivukus cedrosensis Repenning & Tedford, 1977
      • †Protodobenus Horikawa, 1995
        • †Protodobenus japonicus Horikawa, 1995
      • †Pliopedia Kellogg, 1921
        • †Pliopedia pacifica Kellogg, 1921
      • †Ontocetus Leidy, 1859
        • †Ontocetus emmonsi Leidy, 1859
      • †Valenictus Mitchell, 1961
        • †Valenictus chulavistensis Deméré 1994
        • †Valenictus imperialensis Mitchell, 1961
      • Odobenus Brisson, 1762
        • †Odobenus mandanoensis Tomida, 1989
• Panotariidae Velez-Juarbe, 2017
  • †Eotaria Boessenecker & Churchill, 2015
    • †Eotaria circa Velez-Juarbe, 2017
    • †Eotaria crypta Boessenecker & Churchill, 2015
  • Otariidae J. E. Gray, 1825
    • Callorhinae Muizon, 1978
      • †Pithanotaria Kellogg, 1925
        • †Pithanotaria starri Kellogg, 1925
      • Callorhinus J. E. Gray, 1859
        • †Callorhinus inouei (Kohno, 1992) [Thalassoleon inouei Kohno, 1992]
        • †Callorhinus macnallyae (Repenning & Tedford, 1977) [Thalassoleon macnallyae Repenning & Tedford, 1977]
        • †Callorhinus gilmorei Berta & Deméré, 1986
    • Otariinae J. E. Gray, 1825
      • †Thalassoleon Repenning & Tedford, 1977
        • †Thalassoleon mexicanus Repenning & Tedford, 1977
      • Zalophini J. E. Gray, 1869
        • †Proterozetes Barnes et al., 2006
          • †Proterozetes ulysses Barnes et al., 2006
        • †Oriensarctos Mitchell, 1968
          • †Oriensarctos watasei (Matsumoto, 1925) [Eumetopias watasei Matsumoto, 1925]
      • Otariini J. E. Gray, 1825
        • Otaria Péron, 1816
          • †Otaria fischeri Gervais & Ameghino, 1880
        • Neophoca J. E. Gray, 1866
          • †Neophoca palatina King, 1983
        • †Hydrarctos Muizon, 1978
          • †Hydrarctos lomasiensis Muizon, 1978