Conchoraptor

{{speciesbox

|fossil_range = Late Cretaceous,
~{{fossilrange|70}}

|image = Conchoraptor in nest.jpg

|image_caption = Cast mounted in a nesting position

|genus = Conchoraptor

|species = gracilis

|authority = Barsbold, 1986

| display_parents = 3

|parent_authority = Barsbold, 1986

}}

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

File:Conchoraptor skeleton.jpg

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.{{cite book|year=1993|chapter=Conchoraptor|title=The Age of Dinosaurs|author1=Dodson, Peter|author2=Britt, Brooks|author3=Carpenter, Kenneth|author4=Forster, Catherine A.|author5=Gillette, David D.|author6=Norell, Mark A.|author7=Olshevsky, George|author8=Parrish, J. Michael|author9= eishampel, David B.|publisher=Publications International, LTD|pages=136|isbn=0-7853-0443-6}}

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".{{cite book|last1=Barsbold|first1=R.|year=1986|chapter=Raubdinosaurier Oviraptoren|editor1=Vorobyeva, E.I.|title=Herpetologische Untersuchungen in der Mongolischen Volksrepublik|publisher=Akademia Nauk SSSR|pages=210–223}} 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.{{Cite journal |last1=Funston |first1=G.F. |last2=Mendonca |first2=S.E. |last3=Currie |first3=P.J. |last4=Barsbold |first4=R. |date=2018 |title=Oviraptorosaur anatomy, diversity and ecology in the Nemegt Basin |url=https://linkinghub.elsevier.com/retrieve/pii/S0031018217306065 |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |language=en |volume=494 |pages=101–120 |doi=10.1016/j.palaeo.2017.10.023}} Numerous specimens were formally referred to the species later, including some recovered from the Barun Goyot Formation.{{cite journal|author1=Foster, W.|author2=Norell, Mark A.|author3=Balanoff, Amy M.|year=2025|title=Two New Specimens of Conchoraptor gracilis (Theropoda: Oviraptorosauria) from the Late Cretaceous of Mongolia|journal=American Museum Novitates|issue=4033|pages=1–66|doi=10.1206/4033.1}}

Description

File:Conchoraptor Restoration.png]]

Conchoraptor was a small dinosaur, only {{convert|1|–|2|m|ft|sp=us}} 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.{{cite journal|last1=Kundrát|first1=M.|year=2007|title=Avian-like attributes of a virtual brain model of the oviraptorid theropod Conchoraptor gracilis|journal=Naturwissenschaften|volume=94|issue=6|pages=499–504|doi=10.1007/s00114-007-0219-1|pmid=17277940|s2cid=25723660 }}

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.{{cite journal|last1=Fanti|first1=F.|last2=Currie|first2=P.J.| last3=Badamgarav|first3=D.|year=2012|title=New Specimens of Nemegtomaia from the Baruungoyot and Nemegt Formations (Late Cretaceous) of Mongolia]|journal=PLOS ONE|volume=7|issue=2|pages=e31330|doi=10.1371/journal.pone.0031330|pmid=22347465 |pmc=3275628 |doi-access=free }}

{{clade| style=font-size:90%;line-height:90%

|label1=Oviraptoridae

|1={{clade

|1=Oviraptor

|label2=unnamed

|2={{clade

|1=Rinchenia

|2=Citipati }}

|label3=unnamed

|3={{clade

|1=Khaan

|label2=unnamed

|2={{clade

|1=Conchoraptor

|label2=unnamed

|2={{clade

|1=Machairasaurus

|label2= unnamed

|2={{clade

|1="Ingenia" (=Ajancingenia)

|label2= unnamed

|2={{clade

|1=Nemegtomaia

|2=Heyuannia }} }} }} }} }} }} }}

Paleobiology

=Senses=

File:Conchoraptor skeleton from Mongolia.jpg

Internal connections between both ears functioned as resonance chambers and improved hearing.{{cite journal|last1=Kundrát|first1=M.|last2=Janácek|first2=J.|year=2007|title=Cranial pneumatization and auditory perceptions of the oviraptorid dinosaur Conchoraptor gracilis (Theropoda, Maniraptora) from the Late Cretaceous of Mongolia|journal=Naturwissenschaften|volume=94|issue=9|pages=769–778|pmid=17530209|doi=10.1007/s00114-007-0258-7|s2cid=40622976 |url=http://doc.rero.ch/record/15526/files/PAL_E2934.pdf }}

===Feeding===

Originally it was suggested that Conchoraptor had a diet that primarily consisted of mollusks.{{Cite journal |last1=Currie |first1=Philip J. |last2=Godfrey |first2=Stephen J. |last3=Nessov |first3=Lev |date=1993-10-01 |title=New caenagnathid (Dinosauria: Theropoda) specimens from the Upper Cretaceous of North America and Asia |url=http://dx.doi.org/10.1139/e93-196 |journal=Canadian Journal of Earth Sciences |volume=30 |issue=10 |pages=2255–2272 |doi=10.1139/e93-196 |issn=0008-4077}}{{Cite journal |last1=LONGRICH |first1=NICHOLAS R. |last2=CURRIE |first2=PHILIP J. |last3=ZHI-MING |first3=DONG |date=2010-09-16 |title=A new oviraptorid (Dinosauria: Theropoda) from the Upper Cretaceous of Bayan Mandahu, Inner Mongolia |journal=Palaeontology |volume=53 |issue=5 |pages=945–960 |doi=10.1111/j.1475-4983.2010.00968.x |s2cid=128767044 |issn=0031-0239|doi-access=free }}{{Cite web |last=Mike |first=Walley |date=July 28, 2008 |title=Strange Dinosaur Called Conchoraptor |url=https://blog.everythingdinosaur.com/blog/_archives/2008/07/28/strange-dinosaur-called-conchoraptor.html |access-date=2022-08-02 |website=Everything Dinosaur Blog |language=en-US}} 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.{{cite journal |last1=Meade |first1=Luke E. |last2=Ma |first2=Waisum |title=Cranial muscle reconstructions quantify adaptation for high bite forces in Oviraptorosauria |journal=Scientific Reports |date=22 February 2022 |volume=12 |issue=1 |pages=3010 |doi=10.1038/s41598-022-06910-4 |pmid=35194096 |pmc=8863891 |s2cid=247057480 |doi-access=free }}

Paleoenvironment

The Nemegt Formation of Mongolia, is estimated to date back to the Maastrichtian stage, between 70 and 66 million years ago{{cite book |last=Gradstein |first=Felix M. |author2=Ogg, James G. |author3=Smith, Alan G. |year=2005 |title=A Geologic Time Scale 2004 |location=Cambridge |publisher=Cambridge University Press |isbn=978-0-521-78142-8}} of the Late Cretaceous period.{{cite journal |last=Jerzykiewicz |first=Tomasz |author2=Russell, Dale A. |author2-link=Dale Russell |year=1991 |title=Late Mesozoic stratigraphy and vertebrates of the Gobi Basin |journal=Cretaceous Research |volume=12 |issue=4 |pages=345–377 |doi=10.1016/0195-6671(91)90015-5}} 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.