Biology:Sphenopsalis

Short description: Extinct genus of mammals

Sphenopsalis Temporal range: Thanetian ~59–55 Ma PreЄ Є O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Multituberculata
Family:	†Lambdopsalidae
Genus:	†Sphenopsalis
Species:	†S. nobilis
Binomial name
†Sphenopsalis nobilis Matthew, Granger & Simpson, 1928

Sphenopsalis is a genus of extinct mammal from the Paleocene of what is now Central Asia. It was a member of the extinct order Multituberculata, and lies within the suborder Cimolodonta and the superfamily Taeniolabidoidea. The genus was named by William Diller Matthew, W. Granger and George Gaylord Simpson in 1928.

Many workers believe that members of the Taeniolabidoidea, such as Sphenopsalis, are all quite similar. For example, they all share a short wide snout and a blocky head so it is probably instructive to look at a close and more commonly occurring relative, Lambdopsalis bulla, a likely burrower.

This organism is found in the fossil record from from 59-55 million years ago, during the Thanetian age. One distinguishing feature of this genus is a single rooted 4th premolar (P4). Based on the structure of their teeth, Sphenopsalis appears to have been a leaf eater (foliovore). They and/or their close relatives may have been partially adapted to a digging (fossorial) lifestyle.

The one known species, Sphenopsalis nobilis, was also named by Matthew, Granger and Simpson in 1928. It has been found in the Late Paleocene Nomogen and Khashat Formation of Mongolia and China . For many years, this species was only known from a handful of fragmentary teeth and bones, but Mao et al discovered additional specimens in 2016 that allowed for more detailed analysis. The American Museum of Natural History in New York City has several fragmentary specimens in its collection.

References

• Dykes, Trevor. "Mesozoic Mammals;Eucosmodontidae, Microcosmodontidae and Taeniolabidoidea, an internet directory". http://home.arcor.de/ktdykes/taenio.htm. 

• Kielan-Jaworowska Z., Hurum J.H. (2001). "Phylogeny and Systematics of multituberculate mammals". Palaeontology 44 (3): 389–429. doi:10.1111/1475-4983.00185. http://doc.rero.ch/record/14775/files/PAL_E1903.pdf. 

• Kielan-Jaworowska, Zofia; Qi, Tao (1990). "Fossorial adaptations of a Taeniolabidoid Multituberculate mammal from the Eocene of China". Vertebrata Palasiatica 28 (02): 83-94. 

• Kielan-Jaworowska, Kielan; Sloan, Robert E. (1979). "Catopsalis (Multituberculata) from Asia and North America and the problem of taeniolabidid dispersal in the Late Cretaceous". Acta Palaeontologica Polonica 24 (2): 187-197. 

• Mao, Fang-Yuan; Wang, Yang-Qing; Meng, Jin (2016). "New specimens of the multituberculate mammal Sphenopsalis from China: Implications for phylogeny and biology of taeniolabidoids". Acta Palaeontologica Polonica 61 (2): 429-454. doi:10.4202/app.00117.2014. 

• Williamson, Thomas E.; Brusatte, Stephen L.; Secord, Ross; Shelley, Sarah (2016). "A new taeniolabidoid multituberculate (Mammalia) from the middle Puercan of the Nacimiento Formation, New Mexico, and a revision of taeniolabidoid systematics and phylogeny". Zoological Journal of the Linnean Society 177: 183-208. doi:10.1111/zoj.12336. 

• Wilson, Gregory P.; Evans, Alistair R.; Corfe, Ian J.; Smits, Peter D.; Fortelius, Mikael; Jernvall, Jukka (2012). "Adaptive radiation of multituberculate mammals before the extinction of dinosaurs". Nature 483: 457-460. doi:10.1038/nature10880. 

Further reading

• Matthew, et al. (1928), "Paleocene Multituberculates from Mongolia". Am. Museum Novitates 331, p. 1-4.
• Simmons, N.B. and Miao, D. 1986. Paraphyly of Catopsalis (Mammalia: Multituberculata) and its biogeographic implications. University of Wyoming, Contributions to Geology, Special Paper, 3, 87±94.

Wikidata ☰ Q764917 entry