Shuvuuia
Encyclopedia
Shuvuuia is a genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of bird-like 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
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 period of Mongolia
Mongolia
Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...

. It is a member of the family Alvarezsauridae, small coelurosauria
Coelurosauria
Coelurosauria is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. In the past, it was used to refer to all small theropods, although this classification has been abolished...

n dinosaurs which are characterized by short but powerful forelimbs specialized for digging. The type (and only known) species is Shuvuuia deserti, or "desert bird". The name Shuvuuia is derived from the Mongolian word shuvuu (шувуу) meaning "bird".

Description

Shuvuuia was a small and lightly built animal. At 60 cm (2 ft) in length it is one of the smallest known dinosaurs. The skull is lightly built with long and slender jaws and minute teeth. Shuvuuia is unique among non-avian theropods in the skull's ability to perform prokinesis
Cranial kinesis
Cranial kinesis is the term for significant movement of skull bones relative to each other in addition to movement at the joint between the upper and lower jaw. It is usually taken to mean relative movement between the upper jaw and the braincase....

, that is, it could flex its upper jaw independently of its braincase.

The hindlimbs of Shuvuuia were long, slender, and short-toed, which may indicate significant running capabilities. The forelimbs, however, were unusually short and powerfully constructed. Although originally Shuvuuia and other alvarezsaurids were thought to have only a single digit on the front limb, newer specimens show the presence of reduced second and third fingers in addition to the massively enlarged thumb known from previous specimens. Like other alverezsaurids, Shuvuuia may have used its forelimbs to open insect nests, and its slender, unusually mobile jaws to probe after such prey.

Fossils of Shuvuuia are currently known from two locations within the Djadochta Formation
Djadochta Formation
The Djadochta Formation is situated in central Asia and dates from the Late Cretaceous Period. Laid down in the early Campanian, possibly starting in the latest Santonian, it is dated somewhat uncertainly at about 84-75 mya...

: Ukhaa Tolgod and Tögrögiin Shiree. These sites are thought to be about 75 million years old (late Campanian
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...

 age). Contemporary genera included Velociraptor
Velociraptor
Velociraptor is a genus of dromaeosaurid theropod dinosaur that existed approximately 75 to 71 million years ago during the later part of the Cretaceous Period. Two species are currently recognized, although others have been assigned in the past. The type species is V. mongoliensis; fossils...

and Protoceratops
Protoceratops
Protoceratops is a genus of sheep-sized herbivorous ceratopsian dinosaur, from the Upper Cretaceous Period of what is now Mongolia. It was a member of the Protoceratopsidae, a group of early horned dinosaurs...

.

Feathers

The type specimen of Shuvuuia was found surrounded by small, hollow, tube-like structures resembling the rachis
Feather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...

 (central vane) of modern bird feathers. Though highly deteriorated and poorly preserved, biochemical analyses later showed that these structures contain decay products of the protein beta-keratin
Beta-keratin
β-keratin or beta-keratin is rich in stacked β pleated sheets, in contrast to alpha-keratin, a fibrous protein rich in alpha helices.β-keratin is found in reptiles...

, and more significantly, the absence of alpha-keratin. While beta-keratin is found in all integumentary (skin and feather) cells of reptiles and birds, only bird feathers completely lack alpha-keratin. These findings show that, though poorly preserved, Shuvuuia likely possessed a coat of feathers.

In popular culture

Shuvuuia is featured in the first episode of the Discovery Channel
Discovery Channel
Discovery Channel is an American satellite and cable specialty channel , founded by John Hendricks and distributed by Discovery Communications. It is a publicly traded company run by CEO David Zaslav...

 TV series Dinosaur Planet, hunted down by a Velociraptor
Velociraptor
Velociraptor is a genus of dromaeosaurid theropod dinosaur that existed approximately 75 to 71 million years ago during the later part of the Cretaceous Period. Two species are currently recognized, although others have been assigned in the past. The type species is V. mongoliensis; fossils...

but eventually becoming a prey for an Oviraptor
Oviraptor
Oviraptor is a genus of small Mongolian theropod dinosaur, first discovered by the paleontologist Roy Chapman Andrews, and first described by Henry Fairfield Osborn, in 1924...

.

External links

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