Conchoraptor Gracilis

''Conchoraptor'' (meaning "conch plunderer") is a genus of oviraptorid dinosaurs that lived in Asia during the Late Cretaceous epoch, about 70 million years ago. It is known from the Barun Goyot and Nemegt formations of Mongolia.

Discovery

When first discovered in the Red Beds of Hermiin Tsav of the Early Maastrichtian Nemegt Formation by a Polish-Mongolian expedition in 1971, scientists believed that ''Conchoraptor'' was a juvenile ''Oviraptor'' and that the animal's missing crest would have begun to grow when the animal reached sexual maturity. Further study of multiple skeletons showed that ''Conchoraptor'' belonged to a new genus. The hands of ''Conchoraptor'' were a major reason scientists decided to split it off from ''Oviraptor''. Anatomically the hands seemed to be an evolutionary intermediate between those of ''Ajancingenia'' and ''Oviraptor'', making it obvious that this animal was not a member of a known species.

The type species of this new genus, ''Conchoraptor gracilis'', was described and named by Barsbold, in 1986. The generic name is derived from Greek ''konkhè'', "mussel", and Latin ''raptor'', "plunderer". This name reflects Barsbold's hypothesis that oviraptorids, rather than preying primarily upon eggs as had been traditionally thought, may have been specialized to feed on mollusks. The specific name means "gracile" in Latin. The holotype is MPC-D 100/20, a partial skull. Numerous specimens were formally referred to the species later, including some recovered from the Barun Goyot Formation.

Description

''Conchoraptor'' was a small dinosaur, only in length. Unlike many other oviraptorids, ''Conchoraptor'' lacked a head crest. Like its relatives, it lacked teeth. Instead of teeth, oviraptorids had powerful beaks, possibly adapted to crushing mollusk shells. The skull of ''Conchoraptor'' was heavily pneumatised, with most of the bones hollow.

Classification

''Conchoraptor'' was by Barsbold assigned to the Oviraptoridae in 1986. Recent analyses show it was a member of the oviraptorid subfamily Ingeniinae (now Heyuanninae). The cladogram below follows an analysis by Fanti ''et al.'', 2012.

Paleobiology

Senses

Internal connections between both ears functioned as resonance chambers and improved hearing.

Feeding

Originally it was suggested that Conchoraptor had a diet that primarily consisted of mollusks. A 2022 study of the bite force of ''Conchoraptor'' and comparisons with other oviraptorosaurs such as ''Incisivosaurus'', ''Citipati'', and ''Khaan'' instead suggests that ''Conchoraptor'' had a very strong bite force. The moderate jaw gape seen in oviraptorosaurs is indicative of herbivory in the majority of the group, but it is clear they were likely feeding on much tougher or more various types of vegetation than other herbivorous theropods in their environment, such as ornithomimosaurs and therizinosaurs were able to. The examinations suggest oviraptorosaurs may have been powerful-biting generalists or specialists that partook of niche partitioning both in body size and cranial function.

Paleoenvironment

The Nemegt Formation of Mongolia, is estimated to date back to the Maastrichtian stage, between 70 and 66 million years ago of the Late Cretaceous period. During the Late Cretaceous period, the land that is now the Nemegt Formation had an arid environment with fields of sand dunes and only intermittent streams. It is slightly younger than the nearby Djadochta Formation, and seems to have been slightly wetter. This formation is noteworthy for the exquisite preservation of small and fragile dinosaur skeletons, a rare occurrence considering that these fossils are typically broken up and dispersed when found in other rock formations.Novacek, M. J., 1996. "Dinosaurs of the Flaming. Cliffs" Anchor/Doubleday. 367 p.

''Conchoraptor'' shared its habitat with other oviraptorosaurs including ''Avimimus'' and ''Nomingia'', other theropods include troodontids such as ''Tochisaurus'' and ''Zanabazar'', the tyrannosaurids ''Alioramus'' and ''Tarbosaurus''. Ornithischians include the pachycephalosaurs ''Homalocephale'' and ''Prenocephale'', the hadrosaurid ''Saurolophus'', the ankylosaurs ''Saichania'' and ''Tarchia''.

See also

* Timeline of oviraptorosaur research

References

External links

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{{Taxonbar, from=Q132558

Oviraptoridae
Dinosaur genera
Maastrichtian dinosaurs
Nemegt Formation
Fossil taxa described in 1986
Taxa named by Rinchen Barsbold
Dinosaurs of Mongolia