Mesodma

Mesodma Temporal range: 83.6–56  Ma PreꞒ Ꞓ O S D C P T J K Pg N Possible Cenomanian record
life restoration
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	† Multituberculata
Family:	† Neoplagiaulacidae
Genus:	† Mesodma
Species
M. ambigua M. formosa M. hensleighi M. pygmaea M. senecta M. thompsoni

Mesodma is an extinct genus of mammal, a member of the extinct order Multituberculata within the suborder Cimolodonta, family Neoplagiaulacidae. It lived during the upper Cretaceous and Paleocene Periods of what is now North America. The earliest definitive record is from the late Santonian stage strata of the Straight Cliffs Formation. ^[1] A single premolar tooth from the lower Cenomanian stage strata of the Cedar Mountain Formation has been tentatively assigned to this genus based on its similarity, but its describers noted that it is unlikely that Mesodma lived during that time. ^[2]

Species

• Mesodma ambigua
  • Place: Mantua Lentil, Wyoming (USA)
  • Age: Maastrichtian-Puercan, Upper Cretaceous - Paleocene
  • Weight: about 55 g
• Mesodma formosa
  • Place: Hell Creek and Frenchman Formation, USA & Canada. This species is possibly also known from Utah.
  • Age: Maastrichtian-Puercan (Upper Cretaceous to the Paleocene).
  • Weight: about 30 g
• Mesodma hensleighi
  • Place: Hell Creek Formation in the U.S. and in Saskatchewan, Canada.
  • Age: Maastrichtian (Upper Cretaceous).
  • Weight: around 15 g
• Mesodma pygmaea
  • Place: Gidley Quarry, Montana, as well as Wyoming and Alberta, Canada
  • Age: Torrejonian-Tiffanian (Middle Paleocene).
  • Weight: about 8 g
• Mesodma senecta
  • Age: Campanian (Upper Cretaceous)
  • Weight: about 50 g
• Mesodma thompsoni (=M. garfieldensis) ^[3]
  • Place: St Mary River Formation & Montana and Wyoming of the US and Canada
  • Age: Maastrichtian-Puercan, Upper Cretaceous - Paleocene
  • Weight: about 55 g

The species "Mesodma" primaeva from the Judithian of Western Interior of North America was formerly assigned to the genus Mesodma, but subsequently it was made the type species of a separate genus Filikomys . ^[4]

References

1. Eaton, Jeffrey G. (12 June 2006). "Santonian (late Cretaceous) mammals from the John Henry Member of the Straight Cliffs Formation, Grand Staircase-Escalante National Monument, Utah". Journal of Vertebrate Paleontology. 26 (2): 446–460. doi:10.1671/0272-4634(2006)26[446:SLCMFT]2.0.CO;2. S2CID   130526200.
2. Eaton, Jeffrey G.; Cifelli, Richard L. (2001). "Multituberculate mammals from near the Early-Late Cretaceous boundary, Cedar Mountain Formation, Utah". Acta Palaeontologica Polonica. 46 (4): 453–518. S2CID   129909933.
3. Smith, Stephanie M.; Wilson, Gregory P. (2016). "Species Discrimination of Co-Occurring Small Fossil Mammals: A Case Study of the Cretaceous-Paleogene Multituberculate Genus Mesodma". Journal of Mammalian Evolution. 24 (2): 147–157. doi:10.1007/s10914-016-9332-2. S2CID   254703663.
4. Weaver, Lucas N.; Varricchio, David J.; Sargis, Eric J.; Chen, Meng; Freimuth, William J.; Wilson Mantilla, Gregory P. (2020). "Early mammalian social behaviour revealed by multituberculates from a dinosaur nesting site". Nature Ecology & Evolution. 5 (1): 32–37. doi:10.1038/s41559-020-01325-8. PMID   33139921. S2CID   226241443.

Further reading

• Osborn (1891); "A review of the Cretaceous Mammalia". Proc. Acad. Nat. Sci. Phila. 124 - 135.
• Simpson (1929), "American Mesozoic Mammalia". Mem. Peabody Mus. Nat. Hist. iii (i): p. 1-235.
• Clemens (1963), "Fossil mammals of the type Lance formation Wyoming. Part I. Introduction and Multituberculata". Univ. Calif. Pub;. Geol. Sci.48, p. 1-105. (According to Peabody Museum database.)
• Marsh (1889), "Discovery of Cretaceous Mammalia". Am. J. Sci.(3) xxxviii, p. 177-180.
• Archibald (1982), A study of Mammalia and geology across the Cretaceous-Tertiary boundary in Garfield County, Montana. Univ. of Calif. Publ. Geol. Sci. 122xvi+, 286pp.
• Jepsen (1940), "Paleocene faunas of the Polecat Bench formation, Park County, Wyoming". Pro. Amer. Philos. Soc83, p. 217-341, 21 figs., 5 pls.
• Kielan-Jaworowska, Z; Hurum, JH (2001). "Phylogeny and Systematics of multituberculate mammals" (PDF). Palaeontology. 44 (3): 389–429. doi:10.1111/1475-4983.00185. S2CID   83592270.