Palaeanodonta

Palaeanodonta Temporal range: 62.22–30.9 Ma PreꞒ Ꞓ O S D C P T J K Pg N Middle Paleocene – Early Oligocene
From top to bottom: Ernanodon antelios, Xenocranium pileorivale and Metacheiromys marshi
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Clade:	Pholidotamorpha
Order:	†Palaeanodonta Matthew, 1918[1]
Families and genera
[see classification]
Synonyms
list of synonyms: Ernodonta (Ding, 1987) Ernanodonta (Ding, 1987) Palaeanodontiformes (Kinman, 1994) [2] Palaenodonta (Rose, 2008)[3] Palaenodontina (Pearse, 1936)[4]

Palaeanodonta ("ancient toothless animals") is an extinct clade of stem-pangolins. They were insectivorous (myrmecophagous), possibly fossorial, and lived from the middle Paleocene to early Oligocene in North America, Europe and Asia.^[3][5][6] While the taxonomic grouping of Palaeanodonta has been debated,^[7] it is widely thought that they are a sister group to pangolins.^{[8][9][5][10]}

Anatomy

Skull

Palaeanodonts generally have low and caudally-broad skulls, with notable lambdoid crests and inflated bullae and squamosals.^[3]

Teeth

Despite the name of the group and contrary to their pangolin relatives, palaeanodonts are known to have had teeth.^[11][3][10] Early palaeanodonts retained minimal tribosphenic post-canines while later species had peglike or otherwise reduced molar crowns.^[11][3][10] Many also had large, characteristic cuspids.^[11][10]

Classification and phylogeny

Traditional classification

• Order: †Palaeanodonta (Matthew, 1918) (stem-pangolins)^[3]
  • Family: †Epoicotheriidae ^{(paraphyletic family)} (Simpson, 1927)
  • Family: †Escavadodontidae (Rose & Lucas, 2000)
  • Family: †Metacheiromyidae (Wortman, 1903)
  • Incertae sedis:
    • Genus: †Arcticanodon (Rose, 2004)
    • Genus: †Melaniella (Fox, 1984)

Revised classification

• Order: †Palaeanodonta (Matthew, 1918) (stem-pangolins)^[6]
  • Family: †Epoicotheriidae ^{(paraphyletic family)} (Simpson, 1927)
    • Genus: †Alocodontulum (Rose, 1978)
      • †Alocodontulum atopum (Rose, 1977)
    • Genus: †Amelotabes (Rose, 1978)
      • †Amelotabes simpsoni (Rose, 1978)
    • Genus: †Auroratherium (Tong & Wang, 1997)
      • †Auroratherium sinense (Tong & Wang, 1997)
    • Genus: †Dipassalus (Rose, 1991)
      • †Dipassalus oryctes (Rose, 1991)
    • Genus: †Tubulodon (Jepsen, 1932)
      • †Tubulodon taylori (Jepsen, 1932)
    • Subfamily: †Epoicotheriinae ^{(paraphyletic subfamily)} (Simpson, 1927)
      • Genus: †Pentapassalus (Gazin, 1952)
        • †Pentapassalus pearcei (Gazin, 1952)
        • †Pentapassalus woodi (Guthrie, 1967)
      • Genus: †Tetrapassalus (Simpson, 1959)
        • †Tetrapassalus mckennai (Simpson, 1959)
        • †Tetrapassalus proius (West, 1973)
        • †Tetrapassalus sp. A [AMNH 10215] (Rose, 1978)
        • †Tetrapassalus sp. B (Robinson, 1963)
      • (unranked): †Epoicotherium/Xenocranium clade
        • Genus: †Epoicotherium (Simpson, 1927)
          • †Epoicotherium unicum (Douglass, 1905)
        • Genus: †Molaetherium (Storch & Rummel, 1999)
          • †Molaetherium heissigi (Storch & Rummel, 1999)
        • Genus: †Xenocranium (Colbert, 1942)
          • †Xenocranium pileorivale (Colbert, 1942)
  • Family: †Ernanodontidae (Ting, 1979)
    • Genus: †Asiabradypus (Nessov, 1987)
      • †Asiabradypus incompositus (Nessov, 1987)
    • Genus: †Ernanodon (Ting, 1979)
      • †Ernanodon antelios (Ting, 1979)
  • Family: †Escavadodontidae (Rose & Lucas, 2000)
    • Genus: †Escavadodon (Rose & Lucas, 2000)
      • †Escavadodon zygus (Rose & Lucas, 2000)
  • Family: †Metacheiromyidae ^{(paraphyletic family)[6]} (Wortman, 1903)
    • Genus: †Brachianodon (Gunnell & Gingerich, 1993)
      • †Brachianodon westorum (Gunnell & Gingerich, 1993)
    • Genus: †Mylanodon (Secord, 2002)
      • †Mylanodon rosei (Secord, 2002)
    • Subfamily: †Metacheiromyinae ^{(paraphyletic subfamily)[6]} (Wortman, 1903)
      • Genus: †Metacheiromys (Wortman, 1903)
        • †Metacheiromys dasypus (Osborn, 1904)
        • †Metacheiromys marshi (Wortman, 1903)
      • Genus: †Palaeanodon (Matthew, 1918)
        • †Palaeanodon ignavus (Matthew, 1918)
        • †Palaeanodon nievelti (Gingerich, 1989)
        • †Palaeanodon parvulus (Matthew, 1918)
        • †Palaeanodon sp. [Le Quesnoy] (Gheerbrant, 2005)
    • Subfamily: †Propalaeanodontinae (Schoch, 1984)
      • Genus: †Propalaeanodon (Rose, 1979)
        • †Palaeanodon parvulus (Rose, 1979)
  • Incertae sedis:
    • Genus: †Arcticanodon (Rose, 2004)
      • †Arcticanodon dawsonae (Rose, 2004)
    • Genus: †Melaniella (Fox, 1984)
      • †Melaniella timosa (Fox, 1984)

Phylogenetic tree

The phylogenetic relationships of order Palaeanodonta are shown in the following cladogram:^[3][5][6]

Ferae	Pan-Carnivora  Pholidotamorpha  Pholidota (sensu stricto)  †Palaeanodonta  †Escavadodontidae  ?  †Melaniella †Amelotabes †Epoicotheriidae †Epoicotherium †Molaetherium †Xenocranium †Epoicotheriinae †Tetrapassalus †Dipassalus †Alocodontulum †Auroratherium †Pentapassalus †Tubulodon  ?  †Arcticanodon †Propalaeanodontinae †Mylanodon †Brachianodon †Palaeanodon †Metacheiromyinae  †Metacheiromys †Ernanodontidae  (Pholidota sensu lato)	†Epoicotherium/Xenocranium clade †Metacheiromyidae

See also

• Mammal classification
• Pholidotamorpha

References

This page was last edited on 14 May 2023, at 20:56