''Caenagnathasia'' ('recent jaw from

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

') is a small caenagnathid

oviraptorosauria Oviraptorosaurs ("egg thief lizards") are a group of feathered maniraptoran dinosaurs from the Cretaceous Period (geology), Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot-like s ...

theropod Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...

from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

Uzbekistan , image_flag = Flag of Uzbekistan.svg , image_coat = Emblem of Uzbekistan.svg , symbol_type = Emblem of Uzbekistan, Emblem , national_anthem = "State Anthem of Uzbekistan, State Anthem of the Republ ...

Discovery

The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

''Caenagnathasia martinsoni'' was named and described in 1994 by Philip J. Currie, Stephen Godfrey and Lev Nesov. The generic name is a combination of a reference to the species' placement in the

Caenagnathidae Caenagnathidae is a family of derived caenagnathoid dinosaurs from the Cretaceous of North America and Asia. They are a member of the Oviraptorosauria, and relatives of the Oviraptoridae. Like other oviraptorosaurs, caenagnathids had specialize ...

, with Asia, the continent of its provenance. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

honours Gerbert Genrikhovich Martinson. The genus is based on

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 ...

N 401/12457, a pair of fused dentaries of the lower jaws. The specimen was found near Dzharakuduk in layers of the

Bissekty Formation The Bissekty Formation (sometimes referred to as Bissekt) is a formation (geology), geologic formation and Lagerstätte which outcrop, crops out in the Kyzyl Kum desert of Uzbekistan, and dates to the Late Cretaceous Period (geology), Period. Laid ...

, dating to the

Turonian The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...

Coniacian The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded by ...

, around 90 mya, making it the oldest known caenagnathoid. A second specimen was referred to the species, N 402/12457, a right dentary of a slightly smaller individual. Both individuals were adult. In 2015, new material of ''Caenagnathasia'' was described. From the same site as the holotype, the material includes various vertebrae, a

dentary In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone ...

, and a

femur The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femo ...

Description

''Caenagnathasia'' is the smallest known oviraptorosaur and one of the smallest non-avian dinosaurs. The jaw fragments are only a few centimetres long and total skull length has been estimated at . A 2010 estimate by

Gregory S. Paul Gregory Scott Paul (born December 24, 1954) is an American freelance researcher, author and illustrator who works in paleontology. He is best known for his work and research on theropoda, theropod dinosaurs and his detailed illustrations, both l ...

gave it a length of and a weight of . ''Caenagnathasia'' would presumably have resembled other oviraptorosaurs, which were feathered, bird-like dinosaurs with beaked skulls, long necks, and long limbs. Recent studies suggest it was one of the more primitive members of the Caenagnathidae.

Classification

''Caenagnathasia'' was originally assigned to the Caenagnathidae. It was even included in the definition of that clade published by

Hans-Dieter Sues Hans-Dieter Sues (born 1956) is a German-born American palaeontologist who is a Senior Research Geologist and Curator of Vertebrate Paleontology at the National Museum of Natural History of the Smithsonian Institution in Washington, DC. Career ...

. It has been suggested however, that it might have a more basal position in the

Oviraptorosauria Oviraptorosaurs ("egg thief lizards") are a group of feathered maniraptoran dinosaurs from the Cretaceous Period (geology), Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot-like s ...

, outside of the Caenagnathoidea.Holtz, Thomas R. Jr. (2010) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages,'
Winter 2010 Appendix.
/ref> In 2015 after the description of new material, it was found that ''Caenagnathasia'' could confidently be referred to Caenagnathidae.

The below cladogram is based on that resolved in the description of '' Anzu''.

References

External links

Image of ''C. martinsonii'' at The Dinosauria
{{Taxonbar, from=Q134763 Caenagnathidae Dinosaur genera Turonian dinosaurs Bissekty Formation Fossil taxa described in 1994 Taxa named by Philip J. Currie Dinosaurs of Uzbekistan

Discovery

Description

Classification

See also

References

External links