''Ptilodus'' (meaning "soft-haired") is a genus of mammals from the extinct order of

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

, and lived during the

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

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. ''Ptilodus'' was a relatively large multituberculate of in length, which is about the same size as a

squirrel Squirrels are members of the family Sciuridae (), a family that includes small or medium-sized rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrel ...

. Its feet, legs and long tail suggest it was a good climber, so it very possibly led a squirrel-like lifestyle. Like other ptilodontids, it had a very large and elongated last lower

premolar The premolars, also called premolar Tooth (human), teeth, or bicuspids, are transitional teeth located between the Canine tooth, canine and Molar (tooth), molar teeth. In humans, there are two premolars per dental terminology#Quadrant, quadrant in ...

which formed a serrated slicing blade. The genus was named by

paleontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geolo ...

Edward Drinker Cope Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontology, paleontologist, comparative anatomy, comparative anatomist, herpetology, herpetologist, and ichthyology, ichthyologist. Born to a wealthy Quaker fam ...

in 1881. Cope also mistakenly assigned some material belonging to this genus to ''Chirox'' in 1884. Elements from ''

Ectypodus ''Ectypodus'' is an extinct genus of mammals, containing the species ''E. aphronorus, E. childei, E. musculus, E. lovei, E. powelli, E. szalayi'', and ''E. tardus''. ''Ectypodus'' was an arboreal omnivore, living in the Paleocene to Eocene of N ...

'' (Jepsen, 1940) and '' Neoplagiaulax'' have also been reassigned to this genus.

Species

There are seven

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, and others have been proposed at one time or another. ''P. nellieae'' (Bell, 1941) is apparently mentioned in a manuscript, rather than a publication. ''P. sinclairi'' ( Simpson, 1935) seems to have become ''

Parectypodus ''Parectypodus'' (meaning "besides ''Ectypodus''") is an extinct genus of mammals that lived from Late Cretaceous (Maastrichtian) to Eocene time in North America. It is a member of the extinct order of Multituberculata, suborder Cimolodonta, fami ...

sinclairi''. In

botany Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

, ''Ptilodus pyramidatus'' is an extinct

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

n plant.

''P. fractus''

The species ''Ptilodus fractus'' had a body weight of about . Remains have been found in

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

, in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, in Dell Creek deposits dated to the Tiffanian stage of the Paleocene. The species was named by J. A. Door in 1952 ( Scott ''et al.'', 2002, Dorr, 1952), though it may have been amended to its current state by David Krause in 1987.

''P. gnomus''

''Ptilodus gnomus'' is the smallest known member of the genus. Hence, the species epithet 'gnomus', which is

Neo-Latin Neo-LatinSidwell, Keith ''Classical Latin-Medieval Latin-Neo Latin'' in ; others, throughout. (also known as New Latin and Modern Latin) is the style of written Latin used in original literary, scholarly, and scientific works, first in Italy d ...

for 'dwarf'. Remains have been discovered in Wyoming in the United States, and

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

, Canada. They were recovered from the Cochrane 2 deposits of the Paskapoo Formation, which have been dated to the Tiffanian stage of the Paleocene. Remains of this species include over 100

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

, (upper and lower), and at least one fragment of jaw. The teeth range from in length. The fourth lower

(p4) is about 51% shorter than the corresponding tooth in ''P. mediaevus''; 28% less than ''P. kummae''; 15% less than ''P. tsosiensis''; and 5% smaller than ''P. fractus'', which gives some idea of the relative sizes of the various animals. There are also differences in shape and the number of serrations. ( Scott ''et al.'', 2002) :Although more similar in size to homologous teeth referable to ''P. tsosiensis'' and ''P. fractus'', the upper and lower ultimate premolars of this new species most closely resemble those of ''P. mediaevus'' in overall morphology. ( Scott ''et al.'', 2002) A couple of isolated teeth which had been previously identified as perhaps belonging to ''Ectypodus'', have been now been placed within this taxon. All referred specimens are held in the collection of the

University of Alberta The University of Alberta (also known as U of A or UAlberta, ) is a public research university located in Edmonton, Alberta, Canada. It was founded in 1908 by Alexander Cameron Rutherford, the first premier of Alberta, and Henry Marshall Tory, t ...

. The species was named by C. R. Scott, R. C. Fox, and G. P. Youzwyshyn in 2002. Material assigned by Jepsen in 1940, as amended by Gazin in 1956, to ''Ectypodus hazeni'' has also been assigned to this species. There are three species of this

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

known from the Alberta location, two of which have yet to be described. This will be attended to by David W. Krause. ( Scott ''et al.'', 2002, pg. 691).

''P. kummae''

''Ptilodus kummae'' has an estimated weight of . Remains have been discovered in

Roche Percee Roche Percee (2021 Canadian census, 2021 population: ) is a village in the Provinces and territories of Canada, Canadian province of Saskatchewan within the RM of Coalfields No. 4 and Division No. 1, Saskatchewan, Census Division No. 1. The vi ...

Saskatchewan Saskatchewan is a Provinces and territories of Canada, province in Western Canada. It is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and to the south by the ...

in Canada, in deposits from the lower Tiffanian stage of the Paleocene. The species was named by David W. Krause in 1977. ( Krause, 1977) The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

is at Alberta University.

''P. mediaevus''

Remains of ''Ptilodus mediaevus'' have been recovered in

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

, and Wyoming in the United States. They have been unearthed from the deposits of the San Juan Basin, which are dated to the Torrejonian stage of the Paleocene. Cope named the species in 1881 ( Cope, 1881). The species ''Ptilodus feronensis'', or ''Ptilodus ferronensis'', was named C. L. Gazin in 1941 ( Gazin, 1941), but all material was reassigned to ''P. mediaevus'' by Rigby in 1980. In 1929, Granger and Simpson did the same thing to the species ''P. plicatus'', which was originally named by J. W. Gidley in 1909. ''Chirox plicatus'' was named by Cope in 1884. He described it as a

marsupial Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...

in 1884, but it is also part of this species.

''P. montanus''

''Ptilodus montanus'' is a large species, about . A brain cast indicates a well-developed sense of smell. Remains were recovered in Montana, in the rock of the Silberling Quarry, which is dated to the lower Tiffanian stage of the Paleocene. Ptilodus montanus Douglass 1

The species was named by E. Douglass in 1908 ( Douglass, 1908). The species ''P. admiralis'', first described by Hay in 1930; and ''P. gracillis'', first described by J. W. Gidley in 1909 ( Gidley, 1909) are now considered part of this species.

''P. tsosiensis''

''Ptilodus tsosiensis'' has been discovered in New Mexico, the Puercan stage deposits of the Lower Paleocene San Juan Basin. The species was named by R. E. Sloan in 1981 ( Sloan, 1981).

''P. wyomingensis''

Remains of ''Ptilodus wyomingensis'' have been found in the Middle Paleocene deposits of the Rock Bench Quarry, in Wyoming and

North Dakota North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minneso ...

in the United States. The species was named by G. L. Jepsen in 1940 ( Jepsen, 1940).

References

* G. L. Jepsen (1940). Paleocene faunas of the Polecat Bench formation, Park County. ''Wyoming. Pro. Amer. Philos. Soc'' 83, 217–340. * Z. Kielan-Jaworowska & J. H. Hurum (2001). Phylogeny and Systematics of multituberculate mammals. ''Paleontology'' 44, 389–429. * David Krause (1977). Paleocene multituberculates (Mammalia) of the Roche Percee Local Fauna, Ravenscrag Formation, Saskatchewan, Canada. ''Palaeontographica Abt'', A 186, 1–36. * C. R. Scott, R. C. Fox RC, and G. P. Youzwyshyn (2002). New earliest Tiffanian (late Paleocene) mammals from Cochrane 2, southwestern Alberta, Canada. ''Acta Palaeontologica Polonica'' 47 (4), 691–704. * R. E. Sloan (1981). Systematics of Paleocene multituberculates from the San Juan Basin, New Mexico. In Lucas ''et al.'' (Ed.), ''Advances in San Juan Basin paleontology'', 127–160. University of New Mexico Press, Albuquerque. * * Much of this information has been derived fro
MESOZOIC MAMMALS; Ptilodontoidea
an Internet directory. {{Taxonbar, from=Q783958 Paleocene mammals of North America Ptilodontoidea Paleocene mammals Taxa named by Edward Drinker Cope Fossil taxa described in 1881 Prehistoric mammal genera Paleontology in Alberta