Caenagnathasia
Encyclopedia
Caenagnathasia is a small oviraptorosauria
n theropod dinosaur
from the Late Cretaceous
of Uzbekistan
.
The type species
Caenagnathasia martinsoni was named and described in 1993/1994 by Philip Currie
, Stephen Godfrey and Lev Nesov. The generic name is a combination of a reference to the species' placement in the Caenagnathidae, with Asia, the continent of its provenance. The specific name honours Gerbert Genrikhovich Martinson. The genus is based on holotype
N 401/12457, a pair of fused dentaries of the lower jaws. The specimen was found near Dzharakuduk in layers of the Bissekty Formation
, dating to the Turonian
-Coniacian
, 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. It is only from these samples that the species is known.
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 3 inches (7.6 cm). A 2010 estimate by Gregory S. Paul
gave it a length of 2 foot (0.6096 m) and a weight of 3 pounds (1.4 kg). If it were built like all oviraptorosaurs, Caenagnathasia was feathered, warm-blooded and had three fingers on each 'hand' (manus
) and four toes on each 'foot' (pes
), with bone fusion distinctly similar to that of birds. The lower jaws are deep with a steep front edge. They are flat, not strongly convex on top, as with more derived oviraptorosaurs. Whereas the latter are toothless, the lower jaws of Caenagnathasia show the rudiment
s of tooth sockets.
Caenagnathasia was originally assigned to the Caenagnathidae. Using the definition by Hans-Dieter Sues
of that clade
it would even by definition be a member. It has been suggested however, that it might have a more basal position in the Oviraptorosauria
, outside of the Caenagnathoidea
.
Oviraptorosauria
Oviraptorosaurs are a group of feathered maniraptoran dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot - like skulls, with or without bony crests atop the head...
n theropod dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
from the Late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
of Uzbekistan
Uzbekistan
Uzbekistan , officially the Republic of Uzbekistan is a doubly landlocked country in Central Asia and one of the six independent Turkic states. It shares borders with Kazakhstan to the west and to the north, Kyrgyzstan and Tajikistan to the east, and Afghanistan and Turkmenistan to the south....
.
The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
Caenagnathasia martinsoni was named and described in 1993/1994 by Philip Currie
Philip Currie
Philip Henry Wodehouse Currie, 1st Baron Currie GCB , known as Sir Philip Currie between 1885 and 1899, was a British diplomat. He was Ambassador to the Ottoman Empire from 1893 to 1898 and Ambassador to Italy from 1898 to 1902.-Background and education:Currie was the son of Raikes Currie, Member...
, Stephen Godfrey and Lev Nesov. The generic name is a combination of a reference to the species' placement in the Caenagnathidae, with Asia, the continent of its provenance. The specific name honours Gerbert Genrikhovich Martinson. The genus is based on holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
N 401/12457, a pair of fused dentaries of the lower jaws. The specimen was found near Dzharakuduk in layers of the Bissekty Formation
Bissekty Formation
The Bissekty Formation is situated in the Kyzyl Kum desert of Uzbekistan, and dates from the late Cretaceous Period. Laid down in the early the Turonian to Coniacian stages, it is dated to about 90-85 ma .The Bissekty Formation is characterised by a mix of marine, brackish, freshwater, and...
, dating to the Turonian
Turonian
The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...
-Coniacian
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 89.3 ± 1 Ma and 85.8 ± 0.7 Ma...
, 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. It is only from these samples that the species is known.
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 3 inches (7.6 cm). A 2010 estimate by Gregory S. Paul
Gregory S. Paul
Gregory Scott Paul is a freelance researcher, author and illustrator who works in paleontology, and more recently has examined sociology and theology. He is best known for his work and research on theropod dinosaurs and his detailed illustrations, both live and skeletal...
gave it a length of 2 foot (0.6096 m) and a weight of 3 pounds (1.4 kg). If it were built like all oviraptorosaurs, Caenagnathasia was feathered, warm-blooded and had three fingers on each 'hand' (manus
Manus (zoology)
The manus is the zoological term for the distal portion of the fore limb of an animal. In tetrapods, it is the part of the pentadactyl limb that includes the metacarpals and digits . During evolution, it has taken many forms and served a variety of functions...
) and four toes on each 'foot' (pes
Pes (zoology)
The pes is the zoological term for the distal portion of the hind limb of tetrapod animals. It is the part of the pentadactyl limb that includes the metatarsals and digits . During evolution, it has taken many forms and served a variety of functions...
), with bone fusion distinctly similar to that of birds. The lower jaws are deep with a steep front edge. They are flat, not strongly convex on top, as with more derived oviraptorosaurs. Whereas the latter are toothless, the lower jaws of Caenagnathasia show the rudiment
Rudiment
In percussion music, a rudiment is one of the basic patterns used in rudimental drumming. These patterns of drum strokes can be combined in many ways to create music.- History :...
s of tooth sockets.
Caenagnathasia was originally assigned to the Caenagnathidae. Using the definition by Hans-Dieter Sues
Hans-Dieter Sues
Hans-Dieter Sues is a German-born paleontologist who is Senior Scientist and Curator of Vertebrate Paleontology at the National Museum of Natural History of the Smithsonian Institution in Washington, DC. He received his education at Johannes Gutenberg-Universität Mainz , University of Alberta, and...
of that clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
it would even by definition be a member. It has been suggested however, that it might have a more basal position in the Oviraptorosauria
Oviraptorosauria
Oviraptorosaurs are a group of feathered maniraptoran dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot - like skulls, with or without bony crests atop the head...
, outside of the Caenagnathoidea
Caenagnathoidea
Caenagnathoidea is a group of advanced oviraptorosaurian dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot - like skulls, often with bony crests atop the head...
.