Haplocheirus
Encyclopedia
Haplocheirus is a genus
of alvarezsauroid theropod dinosaur
. It is the most basal member of its clade
. It is the oldest known alvarezsauroid, predating all other members by about 63 million years. This also makes it about 15 million years older than the oldest known bird
Archaeopteryx
. Haplocheirus was described in 2010 from a fossil specimen found from the 160 million year old Shishugou Formation
in the Junggar Basin of northwestern China
. The type species
is H. sollers, meaning "simple-handed skillful one", referencing its hypothesized behavior of using its three-fingered hands for activities other alvarezsauroids couldn't, such as catching prey.
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 alvarezsauroid 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...
. It is the most basal member of its 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 is the oldest known alvarezsauroid, predating all other members by about 63 million years. This also makes it about 15 million years older than the oldest known bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
Archaeopteryx
Archaeopteryx
Archaeopteryx , sometimes referred to by its German name Urvogel , is a genus of theropod dinosaur that is closely related to birds. The name derives from the Ancient Greek meaning "ancient", and , meaning "feather" or "wing"...
. Haplocheirus was described in 2010 from a fossil specimen found from the 160 million year old Shishugou Formation
Shishugou Formation
The Shishugou Formation is a geological formation in Xinjiang, China, whose strata date back to the Late Jurassic period. Dinosaur remains are among the fossils that have been recovered from the formation....
in the Junggar Basin of northwestern China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. 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...
is H. sollers, meaning "simple-handed skillful one", referencing its hypothesized behavior of using its three-fingered hands for activities other alvarezsauroids couldn't, such as catching prey.
Description
Haplocheirus was the largest known definite alvarezsauroid, at around 2 meters long. It had an enlarged thumb claw like other alvarezsauroids, but also retained two other functional fingers, unlike more derived alvarezsauroids, where only the thumb was significantly large and clawed. It had long legs and was probably a fast runner.External links
- Richard Stone Bird-Dinosaur Link Firmed Up, And in Brilliant Technicolor Science 29 January 2010: Vol. 327. no. 5965, p. 508, DOI 10.1126/science.327.5965.508
- Doreen Walton New dinosaur discovery solves evolutionary bird puzzle BBC News Thursday, 28 January 2010