''Pseudocrypturus'' is a

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 ...

of extinct paleognathous bird. Three species are known and the type species is ''Pseudocrypturus cercanaxius''. It is a relative of such modern birds as

ostrich Ostriches are large flightless birds. Two living species are recognised, the common ostrich, native to large parts of sub-Saharan Africa, and the Somali ostrich, native to the Horn of Africa. They are the heaviest and largest living birds, w ...

es. It lived in the early

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

. 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 ...

fossil is in the collection of the Smithsonian's

National Museum of Natural History The National Museum of Natural History (NMNH) is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. With 4.4 ...

. It has catalog number USNM 336103. It was collected from the Fossil Butte Member,

Green River Formation The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River (Colorado River), Green River in Colorado, Wyoming, and Utah. The sedimen ...

Lincoln County, Wyoming Lincoln County is a county in the U.S. state of Wyoming. As of the 2020 United States census, the population was 19,581. Its county seat is Kemmerer. Its western border abuts the eastern borders of the states of Idaho and Utah. History Linc ...

.Houde, Peter W. (1988)

Taxonomy

''Pseudocrypturus'' means false

tinamou Tinamous () are members of the order Tinamiformes (), and family Tinamidae (), divided into two distinct subfamily, subfamilies, containing 46 species found in Mexico, Central America, and South America. The word "tinamou" comes from the Carib la ...

. The species name cercanaxius comes from ancient Greek words , tail, and , worthless, in reference to the rudimentary

pygostyle Pygostyle is a skeletal condition in which the final few caudal vertebrae are fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these. The pygostyle is the main component o ...

of this species.

Footnotes

References

* * {{Taxonbar, from=Q7254714 Bird genera Eocene genus extinctions Lithornithidae Paleogene birds of North America Fossil taxa described in 1988 Paleontology in Wyoming Green River Formation Eocene birds of Europe Extinct birds of Europe