Plesiadapiformes

Plesiadapiformes ("Adapid-like" or "near Adapiformes") is a group of Primates, as sister of the Dermoptera.[2][3][4][5] While none of the groups normally directly assigned to this group survived, the group appears actually not to be literally extinct (in the sense of having no living descendants) as the remaining primates (the crown primates or "Euprimates") appear to be derived Plesiadapiformes, as sister of e.g. the Carpolestidae. The term Plesiadapiformes may still be used for all primates which are not crown primates, but this usage is obviously paraphyletic. When the crown primates are cladistically granted, it becomes an obsolete junior synonym to primates.[6] Purgatorius is believed to be a basal Plesiadapiformes.[1]

Plesiadapiformes Temporal range: Paleocene-Eocene, 65–55 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Plesiadapis
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Clade:	†Plesiadapiformes Simons and Tattersall, 1972
Families
Micromomyidae Paromomyidae Picromomyidae Palaechthonidae Picrodontidae Microsyopidae Chronolestidae Plesiadapidae Carpolestidae Purgatoriidae[1] Cladistically included but traditionally excluded crown primates/Euprimates sister: Dermoptera
Synonyms
Primates

Plesiadapiformes first appear in the fossil record between 65 and 55 million years ago,[7] although many were extinct by the beginning of the Eocene. They may have been the first mammals to have finger nails in place of claws.[8] In 1990, K.C. Beard attempted to link the Plesiadapiformes with the order Dermoptera. They proposed that paromomyid Phenacolemur had digital proportions of the fossil indicated gliding habits similar to that of colugos.[9]

In the following simplified cladogram, the crown primates are found to be highly derived Plesiadapiformes, possibly as sister of the Carpolestidae.[5] The crown primates are cladistically granted here into the Plesiadapiformes, and the 'plesiadapiformes' become a junior synonym of the primates. With this tree, the plesiadapiformes are not literally extinct (in the sense of having no surviving descendants). The crown primates are also called "Euprimates" in this context.

Euarchontoglires	Glires   Rodentia (rodents)     Lagomorpha (rabbits, hares, pikas)     Euarchonta   Scandentia (treeshrews)   Primatomorpha   Dermoptera (colugos)   Primates/   †Purgatoriidae       †Micromomyidae       †Microsyopidae         †Paromomyidae     †Palaechthonidae           †Carpolestidae     †Plesiadapidae       Crown Primates           Plesiadapiformes

Alternatively, in 2018, the plesiadapiform were proposed to be more related to Dermoptera, or roughly corresponding to Primatomorpha with both Dermoptera and the primates emerging within this group.[10][11][12] Also in a 2020 paper, the primates and Dermoptera were jointly considered sister to the plesiadapiform Purgatoriidae, resulting in the following phylogenetic tree.[13]

Euarchontoglires	Glires   Rodentia (rodents)     Lagomorpha (rabbits, hares, pikas)     Euarchonta   Scandentia (treeshrews)   Primatomorpha/     †Purgatoriidae   crown Primatomorpha   Dermoptera (colugos)     Primates         †Plesiadapiform s.s.   Plesiadapiformes

Traditionally, they were regarded as a separate extinct order of Primatomorpha, but it now appears that groups such as the extant primates and/or the Dermoptera have emerged in the group.

One possible classification table of plesiadapiform families is listed below.

• PLESIADAPIFORMES
  • Family Micromomyidae
  • Superfamily Paromomyoidea
    • Family Paromomyidae
    • Family Picromomyidae
    • Family Palaechthonidae
    • Family Picrodontidae
    • Family Microsyopidae
  • Superfamily Plesiadapoidea
    • Family Chronolestidae
    • Family Plesiadapidae
  • Superfamily Carpolestoidea
    • Family Carpolestidae

References

1. Scott, Craig S.; Fox, Richard C.; Redman, Cory M. (21 March 2016). "A new species of the basal plesiadapiform Purgatorius (Mammalia, Primates) from the early Paleocene Ravenscrag Formation, Cypress Hills, southwest Saskatchewan, Canada: further taxonomic and dietary diversity in the earliest primates". Canadian Journal of Earth Sciences. doi:10.1139/cjes-2015-0238. hdl:1807/71784.
2. Henke, Winfried; Tattersall, Ian; Hardt, Thorolf (2007). Handbook of Paleoanthropology: Vol I:Principles, Methods and Approaches Vol II:Primate Evolution and Human Origins Vol III:Phylogeny of Hominids. Springer Science & Business Media. p. 839. ISBN 978-3-540-32474-4. Retrieved 25 January 2015.
3. Boyer, Doug M.; Costeur, Loïc; Lipman, Yaron (2012). "Earliest record of Platychoerops(Primates, Plesiadapidae), a new species from Mouras Quarry, Mont de Berru, France". American Journal of Physical Anthropology. 149 (3): 329–346. doi:10.1002/ajpa.22119. ISSN 0002-9483. PMID 22926965.
4. Ni, X.; Meng, J.; Beard, K. C.; Gebo, D. L.; Wang, Y.; Li, C. (2009). "A new tarkadectine primate from the Eocene of Inner Mongolia, China: phylogenetic and biogeographic implications". Proceedings of the Royal Society B: Biological Sciences. 277 (1679): 247–256. doi:10.1098/rspb.2009.0173. ISSN 0962-8452. PMC 2842661. PMID 19386655.
5. Silcox, Mary T.; Bloch, Jonathan I.; Boyer, Doug M.; Chester, Stephen G. B.; López‐Torres, Sergi (2017). "The evolutionary radiation of plesiadapiforms". Evolutionary Anthropology: Issues, News, and Reviews. 26 (2): 74–94. doi:10.1002/evan.21526. ISSN 1520-6505. PMID 28429568.
6. Silcox, Mary T.; López-Torres, Sergi (30 August 2017). "Major Questions in the Study of Primate Origins". Annual Review of Earth and Planetary Sciences. 45 (1): 113–137. doi:10.1146/annurev-earth-063016-015637. ISSN 0084-6597.
7. Paleontologists discover most primitive primate skeleton - PhysOrg.com
8. ""Sleep, First Primates, Earthquakes in the Midwest and Profile: Sang-Mook Lee"". NOVA scienceNOW. Season 4. Episode 8. 9 July 2008. 13:04 minutes in. PBS. Transcripts – NOVA scienceNOW: 9 July 2008.
9. Beard, K. C. (1990). "Gliding behaviour and palaeoecology of the alleged primate family Paromomyidae (Mammalia, Dermoptera)". Nature. 345 (6273): 340–341. doi:10.1038/345340a0.
10. Morse, Paul E.; Chester, Stephen G.B.; Boyer, Doug M.; Smith, Thierry; Smith, Richard; Gigase, Paul; Bloch, Jonathan I. (2019). "New fossils, systematics, and biogeography of the oldest known crown primate Teilhardina from the earliest Eocene of Asia, Europe, and North America". Journal of Human Evolution. 128: 103–131. doi:10.1016/j.jhevol.2018.08.005. PMID 30497682.
11. Godinot, Marc (16 April 2017), "Paleocene and Eocene Primates", in Bezanson, Michele; MacKinnon, Katherine C; Riley, Erin; Campbell, Christina J (eds.), The International Encyclopedia of Primatology, John Wiley & Sons, Inc., pp. 1–9, doi:10.1002/9781119179313.wbprim0331, ISBN 9781119179313
12. Boyer, Doug M.; Maiolino, Stephanie A.; Holroyd, Patricia A.; Morse, Paul E.; Bloch, Jonathan I. (1 September 2018). "Oldest evidence for grooming claws in euprimates". Journal of Human Evolution. 122: 1–22. doi:10.1016/j.jhevol.2018.03.010.
13. Seiffert, Erik R.; Tejedor, Marcelo F.; Fleagle, John G.; Novo, Nelson M.; Cornejo, Fanny M.; Bond, Mariano; de Vries, Dorien; Campbell, Kenneth E. (10 April 2020). "A parapithecid stem anthropoid of African origin in the Paleogene of South America". Science. 368 (6487): 194–197. doi:10.1126/science.aba1135. ISSN 0036-8075.

External links

• Mikko's Phylogeny Archive