''Meniscoessus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of extinct mammal from the Upper

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

Period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

of what is now North America. It was a member of the extinct order

Multituberculata Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, a ...

, lying within the suborder

Cimolodonta Cimolodonta is a taxon of extinct mammals that lived from the Cretaceous to the Eocene. They were some of the more derived members of the extinct order Multituberculata. They probably lived something of a rodent-like existence until their ...

and

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Cimolomyidae Cimolomyidae is a family of fossil mammal within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and the Paleocene of North America and perhaps Mongolia. The family is part of the suborder Cimolodonta. Oth ...

Taxonomy

The genus ''Meniscoessus'' was named by Edward Drinker Cope in 1882. It has also been known under the following names: '' Cimolomys '' (partly); ''Dipriodon'' (

Marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...

1889); ''Halodon'' (Marsh 1889); ''Oracodon'' (Marsh 1889); ''Moeniscoessus''; ''Selenacodon'' (Marsh 1889) (partly); and ''

Tripriodon ''Meniscoessus'' is a genus of extinct mammal from the Upper Cretaceous Period of what is now North America. It was a member of the extinct order Multituberculata, lying within the suborder Cimolodonta and family Cimolomyidae. Taxonomy The ...

'' (Marsh 1889). The generic name has a complicated history. It is attributed to Cope, 1882. Later, this was joined by ''"Meniscoessus"'' (Marsh 1889). The second usage apparently related to teeth described as belonging to small carnivorous dinosaurs. These were further christened ''Dipriodon'', ''Tripriodon'' and others, including ''Triprotodon''. Close similarities were then noticed with an already established dinosaur genus, ''

Paronychodon ''Paronychodon'' (meaning "beside claw tooth") was a theropod dinosaur genus. It is a tooth taxon, often considered dubious because of the fragmentary nature of the fossils, which include "buckets" of teeth from many disparate times and places b ...

'' (Cope 1876), also based on teeth from the

Laramie Formation The Laramie Formation is a geologic formation of Late Cretaceous (Maastrichtian) age, named by Clarence King in 1876 for exposures in northeastern Colorado, in the United States.King, C. 1876. Report of the Geological Exploration of the Fortieth P ...

. Over time, an impressive school of names was synonymized under ''P.'' However, this is now considered a '' nomen dubium''. In 1929,

George Gaylord Simpson George Gaylord Simpson (June 16, 1902 – October 6, 1984) was an American paleontologist. Simpson was perhaps the most influential paleontologist of the twentieth century, and a major participant in the modern synthesis, contributing '' Tempo ...

published ''American Mesozoic Mammalia'' (Mem. of the Peabody Museum, 3 pt. 1; i-xv). The name ''Tripriodon'' ("three saw tooth") was resurrected. These "theropod" teeth were actually mammalian. The mammal ''T.'' since seems to have fallen from use. ''Meniscoessus'' is a valid

multituberculate Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, a ...

, known from high quality remains including many teeth.

Species

The species ''Meniscoessus collomensis'' was named by Jason A. Lillegraven in 1987.

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

remains were found in the Upper Cretaceous strata of the Williams Fork Formation, in

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

(United States). This species is known from only one site. It weighed an estimated 1.4 kg. The species ''Meniscoessus conquistus'' was named by Edward Drinker Cope in 1882. Remains were found in the Maastrichtian (Upper Cretaceous) strata of Colorado and of the

St. Mary River Formation The St. Mary River Formation is a geologic Formation (geology), formation of Late Cretaceous (71.9-67 Mega-annum, Ma) Geochronology, age of the Western Canadian Sedimentary Basin, Western Canada Sedimentary Basin in southwestern Alberta and north ...

of Canada. The species ''Meniscoessus ferox'' was named by Richard C. Fox in 1971. Remains were found in Campanian (Upper Cretaceous) strata of the Upper Milk River Formation of

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

, Canada. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

, collected in 1968, is in the

University of Alberta The University of Alberta, also known as U of A or UAlberta, is a Public university, public research university located in Edmonton, Alberta, Canada. It was founded in 1908 by Alexander Cameron Rutherford,"A Gentleman of Strathcona – Alexande ...

collection. The species ''Meniscoessus intermedius'' was named by Richard C. Fox in 1976. Remains were found in the Campanian - Maastrichtian (Upper Cretaceous) strata of the

Oldman Formation The Oldman Formation is a stratigraphic unit of Late Cretaceous (Campanian stage) age that underlies much of southern Alberta, Canada. It consists primarily of sandstones that were deposited in fluvial channel and floodplain environments. It was ...

of Alberta and

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

and

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

(USA). It is estimated to have weighed about 500 g, as much as a large rat. The species ''Meniscoessus major'' was named by Loris Shano Russell in the 1930s. It is also known as ''Cimolomys major'' (Russell 1936). Remains were found in the Campanian (Upper Cretaceous) strata of

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columb ...

(USA) and Alberta, Canada. The weight of this species has been estimated at around a kilogram. The

is in Alberta. Multituberculate skull

The species ''Meniscoessus robustus'' was named by

Othniel Charles Marsh Othniel Charles Marsh (October 29, 1831 – March 18, 1899) was an American professor of Paleontology in Yale College and President of the National Academy of Sciences. He was one of the preeminent scientists in the field of paleontology. Among ...

in 1889. It has also been known as ''Cimolomys sculptusy''; ''Dipriodon lacunatus''; ''D. lunatus'' (Marsh 1889); ''D. robustus'' (Marsh 1889); ''Halodon sculptus'' (Marsh 1889); ''M. borealis'' (Simpson 1927); ''M. coelatus''; ''M. fragilis''; ''M. greeni'' (Wilson R.W. 1987); ''M. lunatus''; ''M. sculptus''; ''Moeniscoessus robustus''; ''Oracodon anceps'' (Marsh 1889); ''O. conulus'' (Marsh 1892); ''Selenacodon fragilis'' (Marsh 1889); and ''Tripriodon coelatus'' (Marsh 1889). Remains were discovered in Maastrichtian (Upper Cretaceous) and possibly

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

strata of Wyoming, Montana,

South Dakota South Dakota (; Sioux: , ) is a U.S. state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota and Dakota Sioux Native American tribes, who comprise a large porti ...

(USA) and the St. Mary's River Formation in Canada. Marsh authored a swamp of names. The weight of this species is estimated to have been about 3.3 kg. The first usage of ''M. robustus'' seems to go back to Osborn in 1891. The species ''Meniscoessus seminoensis'' was named by Jaelyn J. Eberle and Jason A. Lillegraven in 1998. Remains were found in Campanian - Maastrichtian (Upper Cretaceous) strata of the Ferris Formation in Wyoming. A 3.5 cm lower jaw was found near the Seminoe mountains. It has a close resemblance to ''M. robustus''. It was somewhere between "rat-sized" and 3.5 kilograms, depending upon which source. An alternative name for this location is "Leave No Toad Unturned." Several other names have been in circulation, such as ''Meniscoessus bustus'', ''Meniscoessus caperatus'' (Marsh 1889), and ''Meniscoessus coelatus''. The first is probably a variant of ''M. robustus'', while the latter two seem to have been connected with

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

teeth.

References

* Lillegraven (1987), Stratigraphy and evolutionary implications of a new species of ''Meniscoessus'' (Multituberculata, Mammalia) from the Upper Cretaceous Williams Fork Formation, Moffat County, Colorado. Dakoterra 3, p. 46-56. * Cope (1882), "Mammalia in the Laramie formation." ''

American Naturalist ''The American Naturalist'' is the monthly peer-reviewed scientific journal of the American Society of Naturalists, whose purpose is "to advance and to diffuse knowledge of organic evolution and other broad biological principles so as to enhance t ...

'' xvi, p. 830-831. * Marsh (1889), "Discovery of Cretaceous Mammalia." ''Am. J. Sci.'' (3) xxxviii: 81–92. * Osborn (1891), "A review of the Cretaceous Mammalia." ''Proc. Acad. Nat. Sci., Phila.'', p. 124-135. * Simpson (1929), "American Mesozoic Mammalia." ''Mem. Peabody Mus. Nat. Hist.'' iii (i), p. 1-235. * Wilson (1987), Late Cretaceous (Fox Hills) multituberculates from the Red Owl local fauna of western South Dakota. ''Dakoterra'' 3, p. 118-122. * Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals." ''Paleontology'' 44, p. 389-429. * Fox (1976), Cretaceous mammals (''Meniscoessus intermedius'', new species, and ''

Alphadon ''Alphadon'' (meaning "first tooth") is an extinct genus of small, primitive mammal that was a member of the metatherians, a group of mammals that includes modern-day marsupials. Its fossils were first discovered and named by George Gaylord Simp ...

sp.'') from the lowermost Oldman Formation, Alberta. Canadian Journal of Earth Sciences, 13(9), p. 1216-1222, 4 figs. * Fox (1971), "Early Campanian multituberculates (Mammalia: Allotheria) from the upper Milk River Formation, Alberta". ''Canadian Journal of Earth Sci.'' 8, p. 916-938. * Much of this information has been derived fro

MESOZOIC MAMMALS: "basal"

, Boffius, Boffiidae and

Kogaionidae Kogaionidae is a family of fossil mammals within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and the Paleocene of Europe. Having started as island endemics on Hateg Island during the Upper Cretaceous, ...

, an Internet directory {{Taxonbar, from=Q12901024 Cimolodonts Cretaceous mammals Extinct mammals of North America Hell Creek fauna Laramie Formation Milk River Formation Fossil taxa described in 1882 Taxa named by Edward Drinker Cope Prehistoric mammal genera