Palaeanodonta
Temporal range: 62.22–30.9 Ma Middle Paleocene – Early Oligocene
From top to bottom: Ernanodon antelios, Xenocranium pileorivale and Metacheiromys marshi
Scientific classification Edit this 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

Revised classification

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

See also

References

  1. ^ W. D. Matthew (1918.) "A revision of the Lower Eocene Wasatch and Wind River faunas. Part V. Insectivora (Continued), Glires, Edentata." Bulletin of the American Museum of Natural History 38(16):429-483
  2. ^ Kenneth E. Kinman (1994.) "The Kinman system: toward a stable cladisto-eclectic classification of organisms: living and extinct, 48 phyla, 269 classes, 1,719 orders"
  3. ^ a b c d e f g Rose, K. D. (2008). "9. Palaeanodonta and Pholidota". In Janis, C. M.; Gunnell, G. F.; Uhen, M. D. (eds.). Evolution of Tertiary Mammals of North America. Cambridge University Press. pp. 135–146. doi:10.1017/CBO9780511541438.010.
  4. ^ Arthur Sperry Pearse (1936.) "Zoological names. A list of phyla, classes, and orders, prepared for section F, American Association for the Advancement of Science" American Association for the Advancement of Science
  5. ^ a b c Gaudin, T. J.; Emry, R. J.; Wible, J. R. (2009). "The Phylogeny of Living and Extinct Pangolins (Mammalia, Pholidota) and Associated Taxa: A Morphology Based Analysis". Journal of Mammalian Evolution. 16: 235. doi:10.1007/s10914-009-9119-9.
  6. ^ a b c d e Kondrashov, Peter; Agadjanian, Alexandre K. (2012). "A nearly complete skeleton of Ernanodon (Mammalia, Palaeanodonta) from Mongolia: morphofunctional analysis". Journal of Vertebrate Paleontology. 32 (5): 983–1001. doi:10.1080/02724634.2012.694319. ISSN 0272-4634.
  7. ^ Averianov, A. O. & Lopatin, A. V. (2014.) "High-level systematics of placental mammals: Current status of the problem." Biology Bulletin, 41(9), 801–816.
  8. ^ McKenna, M. C.; Bell, S. K. (1997). Classification of Mammals: Above the Species Level. Columbia University Press. pp. 220–221. ISBN 978-0-231-52853-5.
  9. ^ Rose, K. D.; Emry, R. J.; Gaudin, T. J.; Storch, G. (2005). "Xenarthra and Pholidota". In Rose, K. D.; Archibald, J. D. (eds.). The Rise of Placental Mammals. Origins and Relationships of the Major Extant Clades. Johns Hopkins University Press. pp. 106–126. ISBN 978-0-8018-8022-3.
  10. ^ a b c d Ungar, P. S. (2010). "Cenozoic Mammal Evolution". Mammal Teeth: Origin, Evolution, and Diversity. pp. 110–126. ISBN 978-0-8018-9668-2.
  11. ^ a b c Rose, K. D.; Lucas, S. G. (2000). "An early Paleocene palaeanodont (Mammalia, ?Pholidota) from New Mexico, and the origin of Palaeanodonta". Journal of Vertebrate Paleontology. 20 (1): 139–156. doi:10.1671/0272-4634(2000)020[0139:AEPPMP]2.0.CO;2.
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