''Nqwebasaurus'' (; anglicized as or ) is a basal

coelurosaur Coelurosauria (; from Greek, meaning "hollow tailed lizards") is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. Coelurosauria is a subgroup of theropod dinosaurs that includes compsognathids, tyran ...

and is the basal-most member of the coelurosaurian clade

Ornithomimosauria Ornithomimosauria ("bird-mimic lizards") are theropod dinosaurs which bore a superficial resemblance to the modern-day ostrich. They were fast, omnivorous or herbivorous dinosaurs from the Cretaceous Period of Laurasia (now Asia, Europe and Nor ...

from the Early

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...

. The name ''Nqwebasaurus'' is derived from the

Xhosa Xhosa may refer to: * Xhosa people, a nation, and ethnic group, who live in south-central and southeasterly region of South Africa * Xhosa language, one of the 11 official languages of South Africa, principally spoken by the Xhosa people See als ...

word "Nqweba" which is the local name for the Kirkwood district, and "thwazi" is ancient Xhosa for "fast runner". Currently it is the oldest coelurosaur in

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

and shows that basal coelurosaurian dinosaurs inhabited Gondwana 50 million years earlier than previously thought. The

type specimen In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes th ...

of ''Nqwebasaurus'' was discovered by William J. de Klerk who is affiliated with the

Albany Museum The Albany Museum, South Africa is situated in Grahamstown in South Africa, is affiliated to Rhodes University and dates back to 1855,Chinsamy, Anusuya. (1997). "Albany Museum, Grahamstown, South Africa." ''Encyclopedia of Dinosaurs''. Edited by ...

Grahamstown Makhanda, also known as Grahamstown, is a town of about 140,000 people in the Eastern Cape province of South Africa. It is situated about northeast of Port Elizabeth and southwest of East London. Makhanda is the largest town in the Makana ...

. It is the only fossil of its species found to date and was found in the

Kirkwood Formation The Kirkwood Formation is a geological Geological formation, formation found in the Eastern and Western Cape provinces in South Africa. It is one of the four formations found within the Uitenhage Group of the Algoa Basin – its type locality – ...

of the Uitenhage Group. ''Nqwebasaurus'' has the unofficial nickname "Kirky", due to being found in the Kirkwood.

History of discovery

''Nqwebasaurus'' was first discovered by William J. de Klerk and Callum Ross in July 1996 during a joint expedition led by the

and Stony Brook in New York, United States, where Callum Ross was affiliated at the time. The fossil is remarkably complete and is considered an extremely rare find as no coelurosaur fossils had previously been found in Africa at this time. No new ''Nqwebasaurus'' fossils have been discovered since.

Description

''Nqwebasaurus'' is considered to have been a small to medium-sized ornithomimosaur. The type specimen is approximately 30 cm (1 ft) high and is estimated to have been 90 cm (3 ft) long, although its complete length is not known due to the caudal vertebrae of the type specimen being incomplete. Gregory S. Paul estimated its adult size at in length and in body mass. In addition the type specimen is thought to be a late juvenile, although with the type specimen being the only

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

representing its species it is currently not possible to compare the fossil with another member of its species. ''Nqwebasaurus'' has a long, three-fingered hand which includes a partially opposable thumb with a recurved claw. The claws on its hands differ in shape where the claws of the first and second digits are recurved and the third claw is not. This trait is unusual in theropod dinosaurs, however, it has been observed in some ornithomimosaurs such as ''

Struthiomimus ''Struthiomimus'' (meaning "ostrich mimic", from the Greek στρούθειος/''stroutheios'' meaning "of the ostrich" and μῖμος/''mimos'' meaning "mimic" or "imitator") is a genus of ornithomimid dinosaurs from the late Cretaceous of No ...

''. ''Nqwebasaurus'' also lacks serrations on its maxillary teeth, has a reduced dentition, and contains

gastrolith A gastrolith, also called a stomach stone or gizzard stone, is a rock held inside a gastrointestinal tract. Gastroliths in some species are retained in the muscular gizzard and used to grind food in animals lacking suitable grinding teeth. In oth ...

s in its abdominal cavity. Again this is unusual trait for carnivorous theropod dinosaurs as gastroliths are more commonly found in herbivorous vertebrates and modern ostriches. Due to these morphological traits, ''Nqwebasaurus'' is thought to have been a herbivore. As more basal theropod species, especially those on the evolutionary line to birds, had feathers it is accepted that ''Nqwebasaurus'' was likely at least partially feathered or had a feather coat for

thermoregulation Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...

Classification

More recent

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

analyses that include ''Nqwebasaurus'' support its current position as the basalmost member of

, one of the most basal clades of Coelurosauria, and the sister taxon of

Maniraptora Maniraptora is a clade of coelurosaurian dinosaurs which includes the birds and the non-avian dinosaurs that were more closely related to them than to ''Ornithomimus velox''. It contains the major subgroups Avialae, Deinonychosauria, Oviraptoros ...

. However, new fossil material of coelurosaurs from the Early Cretaceous of Gondwana is much needed in order to gain a further understanding of Gondwanan coelurosaur

phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spe ...

. The cladogram below follows an analysis by Yuong-Nam Lee, Rinchen Barsbold, Philip J. Currie, Yoshitsugu Kobayashi, Hang-Jae Lee, Pascal Godefroit, François Escuillié & Tsogtbaatar Chinzorig. The analysis was published in 2014, and displays the current phylogenetic position of ''Nqwebasaurus''.

References

{{Portalbar, Dinosaurs, Cretaceous, South Africa Ornithomimosaurs Early Cretaceous dinosaurs of Africa Cretaceous South Africa Fossils of South Africa Fossil taxa described in 2000 Taxa named by Catherine Forster Taxa named by Scott D. Sampson Xhosa language

History of discovery

Description

Classification

See also

References