Conchoraptor

Conchoraptor (meaning "conch plunderer") is a genus of oviraptorid dinosaur from the late Cretaceous Period of what is now Asia.

Conchoraptor
Temporal range: Late Cretaceous, 70–66 Ma
Conchoraptor in nest
Cast mounted in a nesting position
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Saurischia
Suborder: Theropoda
Family: Oviraptoridae
Genus: Conchoraptor
Barsbold, 1986
Species:
C. gracilis
Binomial name
Conchoraptor gracilis
Barsbold, 1986

Description

Conchoraptor gracilis profile1
Profile of Conchoraptor gracilis
Ingenia yanshini
Skull

Conchoraptor was a small dinosaur, only 1–2 meters (3.3-6.6 feet) in length.[1] Unlike many other oviraptorids, Conchoraptor lacked a head crest.[1] Like its relatives, it lacked teeth. Instead of teeth, oviraptorids had powerful beaks, possibly adapted to crushing mollusk shells.[1] The skull of Conchoraptor was heavily pneumatised, with most of the bones hollow.[2] Internal connections between both ears functioned as resonance chambers and improved hearing.[3]

Discovery

When first discovered in the Red Beds of Hermiin Tsav of the Early Maastrichtian Nemegt Formation by a Polish-Mongolian expedition in 1971,[1] scientists believed that Conchoraptor was a juvenile Oviraptor and that the animal's missing crest would have begun to grow when the animal reaching sexual maturity.[1] Further study of multiple skeletons showed that Conchoraptor belonged in a new genus.[1] The hands of Conchoraptor were a major reason that scientists decided to split it off from Oviraptor.[1] 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.[1]

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".[4] 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.[1] The specific name means "gracile" in Latin. The holotype is IGM 100/20, a partial skeleton with skull. Later about two dozen specimens were formally referred to the species.

Classification

Conchoraptor gracilis
Skeletal restoration

Conchoraptor was by Barsbold assigned to the Oviraptoridae in 1986. Recent analyses show it was a member of the oviraptorid subfamily Ingeniinae.

The cladogram below follows an analysis by Fanti et al., 2012.[5]

Oviraptoridae

Oviraptor

unnamed

Rinchenia

Citipati

unnamed

Khaan

unnamed

Conchoraptor

unnamed

Machairasaurus

unnamed

"Ingenia" (=Ajancingenia)

unnamed

Nemegtomaia

Heyuannia

Paleoecology

Habitat

Conchoraptor subadult
Subadult specimen

The Nemegt Formation of Mongolia, is estimated to date back to the Maastrichtian stage, between 70 and 66 million years ago[6] of the Late Cretaceous period.[7] 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.[7] 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.[8]

Paleofauna

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

Related animals

References

  1. ^ a b c d e f g h i "Conchoraptor." In: Dodson, Peter & Britt, Brooks & Carpenter, Kenneth & Forster, Catherine A. & Gillette, David D. & Norell, Mark A. & Olshevsky, George & Parrish, J. Michael & Weishampel, David B. The Age of Dinosaurs. Publications International, LTD. p. 136. ISBN 0-7853-0443-6.
  2. ^ Kundrat, M. 2007, "Avian-like attributes of a virtual brain model of the oviraptorid theropod Conchoraptor gracilis", Naturwissenschaften 94: 499-504
  3. ^ Kundrat M. and Janacek, J., 2007, "Cranial pneumatization and auditory perceptions of the oviraptorid dinosaur Conchoraptor gracilis (Theropoda, Maniraptora) from the Late Cretaceous of Mongolia", Naturwissenschaften 94:769–778
  4. ^ Rinchen Barsbold, 1986, "Raubdinosaurier Oviraptoren". In: Vorobyeva, E. I. (ed.), Herpetologische Untersuchungen in der Mongolischen Volksrepublik. Akademia Nauk SSSR. pp. 210-223
  5. ^ Fanti F, Currie PJ, Badamgarav D (2012). "New Specimens of Nemegtomaia from the Baruungoyot and Nemegt Formations (Late Cretaceous) of Mongolia." PLoS ONE, 7(2): e31330. doi:10.1371/journal.pone.0031330
  6. ^ Gradstein, Felix M.; Ogg, James G.; Smith, Alan G. (2005). A Geologic Time Scale 2004. Cambridge: Cambridge University Press. ISBN 978-0-521-78142-8.
  7. ^ a b Jerzykiewicz, Tomasz; Russell, Dale A. (1991). "Late Mesozoic stratigraphy and vertebrates of the Gobi Basin". Cretaceous Research. 12 (4): 345–377. doi:10.1016/0195-6671(91)90015-5.
  8. ^ Novacek, M. J., 1996. "Dinosaurs of the Flaming. Cliffs" Anchor/Doubleday. 367 p.
1986 in paleontology

Paleontology or palaeontology (from Greek: paleo, "ancient"; ontos, "being"; and logos, "knowledge") is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1986.

Avimimus

Avimimus ( AY-vi-MY-məs), meaning "bird mimic" (Latin avis = bird + mimus = mimic), was a genus of oviraptorosaurian theropod dinosaur, named for its bird-like characteristics, that lived in the late Cretaceous in what is now Mongolia, around 70 million years ago.

C. gracilis

C. gracilis may refer to:

Caecilia gracilis, an amphibian species

Cancer gracilis, the graceful rock crab or slender crab, a crab species

Cardioglossa gracilis, a frog species

Catocala gracilis, the graceful underwing, a moth species

Chapmannia gracilis, a legume species found only in Yemen

Charassognathus gracilis, an extinct cynodontia species

Citrus gracilis, the Humpty Doo lime or Kakadu lime, a straggly shrub species found in the Northern Territory, Australia

Clarkia gracilis, the slender clarkia, a wildflower species native to California

Coccothrinax gracilis, the latanier, a palm species endemic to the island of Hispaniola

Coelus gracilis, a beetle species endemic to the United States

Coelurus gracilis, a coelurosaur dinosaur species

Coluber gracilis, the graceful racer, a snake species found in India

Conchoraptor gracilis, an oviraptorid dinosaur species

Coniogramme gracilis, a fern species

Coursetia gracilis, a legume species found only in Ecuador

Cordicephalus gracilis, an extinct prehistoric frog species

Crania gracilis, a brachiopod species in the genus Crania

Cricosaurus gracilis, an extinct marine crocodyliform species

Crocodilichthys gracilis, the lizard triplefin, a fish species

Cryptotis gracilis, the Talamancan small-eared shrew, a mammal species

Cynosurus gracilis, a grass species in the genus Cynosurus

Caenagnathoidea

Caenagnathoidea ("recent jaw forms") is a group of advanced oviraptorosaurian dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot-like skulls, often with bony crests atop the head. They ranged in size from Caudipteryx, which was the size of a turkey, to the 8 meter long, 1.4 ton Gigantoraptor. The group (along with all maniraptoran dinosaurs) is close to the ancestry of birds. The most complete specimens have been found in Asia, representing members of the sub-group Oviraptorinae. Notable but fragmentary remains are also known from North America, almost all of which belong to the subgroup Elmisaurinae.The earliest definitive caenangnathoid is Microvenator celer, which dates to the late Aptian age of the early Cretaceous period, though the slightly earlier Caudipteryx from the lower Yixian Formation of China, may also be a member of this group.

Corythoraptor

Corythoraptor (meaning "crested raptor") is a genus of crested oviraptorid theropod dinosaur from the Nanxiong Formation of China. It is known from one species, C. jacobsi, named after palaeontologist Louis L. Jacobs. Including it, there are seven oviraptorids known from the Nanxiong Formation, showing a high level of diversity in the area, and that the different taxa may have occupied different ecological niches.

Hagryphus

Hagryphus ("Ha's griffin"), is an oviraptorosaurian theropod dinosaur from the Upper Cretaceous Period of what is now Utah.

Heyuannia

Heyuannia ("from Heyuan") is a genus of oviraptorid dinosaur that lived during the Late Cretaceous Period in China. It was the first oviraptorid found in that country; most others were found in neighbouring Mongolia. Two species are known: H. huangi, named by Lü Junchang in 2002; and H. yanshini, originally named as a separate genus Ingenia by Rinchen Barsbold in 1981 (and renamed to Ajancingenia in 2013 due to the preoccupation of Ingenia).

Huanansaurus

Huanansaurus is an extinct genus of oviraptorid dinosaur that lived approximately 72 million years ago, between the Campanian and Maastrichtian, during the latter part of the Cretaceous period in what is now China, in the Nanxiong Formation.

Khaan

Khaan (; Mongol [χaːŋ] 'lord') was an oviraptorid dinosaur that was found in the Djadochta Formation of Mongolia and lived in the Late Cretaceous Period (Campanian), 75 million years ago.

List of non-avian dinosaur species preserved with evidence of feathers

Several non-avian dinosaurs were feathered. Direct evidence of feathers exists for the following species, listed in the order currently accepted evidence was first published. In all examples, the evidence described consists of feather impressions, except those genera inferred to have had feathers based on skeletal or chemical evidence, such as the presence of quill knobs (the anchor points for wing feathers on the forelimb) or a pygostyle (the fused vertebrae at the tail tip which often supports large feathers).

Ostromia crassipes (1970)

Avimimus portentosus (inferred 1987: ulnar ridge)

Sinosauropteryx prima (1996)

Fulicopus lyellii, an ichnotaxon, possible squatting Dilophosaurus or similar. (1996)

Protarchaeopteryx robusta (1997)

GMV 2124 (1997)

Caudipteryx zoui (1998)

Rahonavis ostromi (inferred 1998: quill knobs; possibly avialan)

Shuvuuia deserti (1999)

Beipiaosaurus inexpectus (1999)

Sinornithosaurus millenii (1999)

Caudipteryx dongi (2000)

Caudipteryx sp. (2000)

Microraptor zhaoianus (2000)

Nomingia gobiensis (inferred 2000: pygostyle)

Psittacosaurus sp.? (2002)

Scansoriopteryx heilmanni (2002; possibly avialan)

Yixianosaurus longimanus (2003)

Dilong paradoxus (2004)

Pedopenna daohugouensis (2005; possibly avialan)

Jinfengopteryx elegans (2005)

Juravenator starki (2006)

Sinocalliopteryx gigas (2007)

Velociraptor mongoliensis (inferred 2007: quill knobs)

Epidexipteryx hui (2008; possibly avialan)

Similicaudipteryx yixianensis (inferred 2008: pygostyle; confirmed 2010)

Anchiornis huxleyi (2009; possibly avialan)

Tianyulong confuciusi? (2009)

Concavenator corcovatus? (inferred 2010: quill knobs?)

Xiaotingia zhengi (2011; possibly avialan)

Yutyrannus huali (2012)

Sciurumimus albersdoerferi (2012)

Ornithomimus edmontonicus (2012)

Ningyuansaurus wangi (2012)

Eosinopteryx brevipenna (2013; possibly avialan)

Jianchangosaurus yixianensis (2013)

Aurornis xui (2013; possibly avialan)

Changyuraptor yangi (2014)

Kulindadromeus zabaikalicus? (2014)

Citipati osmolskae (inferred 2014: pygostyle)

Conchoraptor gracilis (inferred 2014: pygostyle)

Deinocheirus mirificus? (inferred 2014: pygostyle)

Yi qi (2015)

Ornithomimus sp. (2015)

Zhenyuanlong suni (2015)

Dakotaraptor steini (inferred 2015: quill knobs)

Apatoraptor pennatus (inferred 2016: quill knobs)

Jianianhualong tengi (2017)

Serikornis sungei (2017)

Caihong juji (2018)Note that the filamentous structures in some ornithischian dinosaurs (Psittacosaurus, Tianyulong and Kulindadromeus) and the pycnofibres found in some pterosaurs may or may not be homologous with the feathers of theropods.

Machairasaurus

Machairasaurus is a genus of oviraptorid dinosaur which was found in the Bayan Mandahu Formation, China dating to the late Cretaceous period.During the Sino-Canadian expeditions of 1988 and 1990 some skeletons of unknown oviraptorosaurians were discovered by Philip J. Currie in Inner Mongolia. Based on two of these a new genus was named and described by Nicholas R. Longrich, Currie and Dong Zhiming in 2010 with as type species Machairasaurus leptonychus. The generic name is derived from Greek μάχαιρα (makhaira), "short scimitar". The specific name is derived from Greek λεπτός (leptos), "slender", and ὄνυξ (onyx), "claw". The species name as a whole refers to the sabre-like claws of the hand.The holotype, IVPP V15979, was found in layers of the Bayan Mandahu dating from the late Campanian. It mainly consists of a left frontlimb, including the lower end of the lower arm, two carpal bones and a complete hand. Also some fragmentary foot elements were present. The other find is the paratype, IVPP V15980, consisting of a very fragmentary skeleton including tail vertebrae, chevrons, ribs, phalanges of the hands, fragments of the second and fourth metatarsals and pedal phalanges.Five oviraptorid specimens associated with a nest, the female having been found brooding near the eggs, may belong to Machairasaurus.Machairasaurus was a small bipedal theropod. The describers established a single autapomorphy, unique derived trait: the hand claws are very elongated and blade-like in side view, with a length four times that of the joint height. The long claws would be proof that basal oviraptorids used their hands to pull down branches; the more curved claws of more derived forms would have served to dig up roots.Machairasaurus was in 2010 assigned to the Oviraptoridae, more precisely to the Ingeniinae. It formed a smaller clade with "Ingenia" yanshini, Heyuannia huangi, Conchoraptor gracilis, and Nemegtomaia barsboldi.

Nemegt Formation

The Nemegt Formation (or Nemegtskaya Svita) is a geological formation in the Gobi Desert of Mongolia, dating to the Late Cretaceous. It overlies and sometimes interfingers with the Barun Goyot Formation. Interfingering has been noted at the stratotype (Red Walls) and Khermeen Tsav. It consists of river channel sediments and contains fossils of fish, turtles, crocodilians, and a diverse fauna of dinosaurs, including birds. The climate associated with it was wetter than when preceding formations were deposited; there seems to have existed at least some degree of forest cover. Fossilized trunks have been also found.

There has been no absolute dating of the Nemegt Formation. It is, however, almost certainly early Maastrichtian c 71-70 Ma. Gradzinski and others considered a Campanian age possible but more recent research indicates otherwise. A Campanian age no longer seems credible, because the Alagteegian (or lower Djadokhtan, at the locality "Chuluut Uul") has been radiometrically dated at about 73.5 Ma or even younger (a more recent K/Ar date is 71.6 +/- 1.6 Ma). The c 73.5 (or perhaps 72) Ma Alagteegian is separated from the Nemegt by the "classic" Djadokhtan (e.g. Bayan Dzag), later Djadohktan (represented by Ukhaa Tolgod) and Barungoyotian (Khulsan). All these intervening horizons almost certainly represent more than the 1.5 million years between the dated Alagteegian level and the onset of Maastrichtian time (72.1 million Ma according to current dating). Ergo the Nemegt is entirely Maastrichtian. See also Shuvalov, Sochava and Martinsson The Age of Dinosaurs in Russia and Mongolia. The presence of Saurolophus further supports an early Maastrichtian age as the same genus occurs in the early Maastrichtian Horseshoe Canyon formation.

Nemegtomaia

Nemegtomaia is a genus of oviraptorid dinosaur from what is now Mongolia that lived in the Late Cretaceous Period, about 70 million years ago. The first specimen was found in 1996, and became the basis of the new genus and species N. barsboldi in 2004. The original genus name was Nemegtia, but this was changed to Nemegtomaia in 2005, as the former name was preoccupied. The first part of the generic name refers to the Nemegt Basin, where the animal was found, and the second part means "good mother", in reference to the fact that oviraptorids are known to have brooded their eggs. The specific name honours the palaeontologist Rinchen Barsbold. Two more specimens were found in 2007, one of which was found on top of a nest with eggs, but the dinosaur had received its genus name before it was found associated with eggs.

Nemegtomaia is estimated to have been around 2 m (7 ft) in length, and to have weighed 40 kg (85 lb). As an oviraptorosaur, it would have been feathered. It had a deep, narrow, and short skull, with an arched crest. It was toothless, had a short snout with a parrot-like beak, and a pair of tooth-like projections on its palate. It had three fingers; the first was largest and bore a strong claw. Nemegtomaia is classified as a member of the oviraptorid subfamily Ingeniinae, and it the only known member of this group with a cranial crest. Though Nemegtomaia has been used to suggest that oviraptorosaurs were flightless birds, the clade is generally considered a group of non-avian dinosaurs.

The nesting Nemegtomaia specimen was placed on top of what was probably a ring of eggs, with its arms folded across them. None of the eggs are complete, but they are estimated to have been 5 to 6 cm (2 to 2.3 in) wide and 14 to 16 cm (5 to 6 in) long when intact. The specimen was found in a stratigraphic area that indicates Nemegtomaia preferred nesting near streams that would provide soft, sandy substrate and food. Nemegtomaia may have protected its eggs by covering them with its tail and wing feathers. The skeleton of the nesting specimen has damage that indicates it was scavenged by skin beetles. The diet of oviraptorids is uncertain, but their skulls are most similar to other animals that are known or thought to have been herbivorous. Nemegtomaia is known from the Nemegt and Baruungoyot Formations, which are thought to represent humid and arid environments that coexisted in the same area,

Oviraptor

Oviraptor is a genus of small Mongolian theropod dinosaurs, first discovered by technician George Olsen in an expedition led by Roy Chapman Andrews, and first described by Henry Fairfield Osborn, in 1924. Its name is Latin for 'egg taker' or "egg seizer", referring to the fact that the first fossil specimen was discovered atop a pile of what were thought to be Protoceratops eggs, and the specific name philoceratops means "lover of ceratopsians", also given as a result of this find. In his 1924 paper, Osborn explained that the name was given due to the close proximity of the skull of Oviraptor to the nest (it was separated from the eggs by only 4 inches or 10 centimetres of sand). However, Osborn also suggested that the name Oviraptor "may entirely mislead us as to its feeding habits and belie its character". In the 1990s, the discovery of nesting oviraptorids like Citipati proved that Osborn was correct in his caution regarding the name. These finds showed that the eggs in question probably belonged to Oviraptor itself, and that the specimen was actually brooding its eggs, when it died at the nest.

Oviraptor lived in the late Cretaceous period, during the late Campanian stage about 75 million years ago; only one definitive specimen is known (with associated eggs), from the Djadokhta Formation of Mongolia, though a possible second specimen (also with eggs) comes from the northeast region of Inner Mongolia, China, in an area called Bayan Mandahu.

Oviraptoridae

Oviraptoridae is a group of bird-like, herbivorous and omnivorous maniraptoran dinosaurs. Oviraptorids are characterized by their toothless, parrot-like beaks and, in some cases, elaborate crests. They were generally small, measuring between one and two metres long in most cases, though some possible oviraptorids were enormous. Oviraptorids are currently known only from the Late Cretaceous of Asia, with the most well-known species and complete specimens found only in the Gobi Desert of Mongolia and northwestern China.

Oviraptorosauria

Oviraptorosaurs ("egg thief lizards") are a group of feathered maniraptoran dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot-like skulls, with or without bony crests atop the head. They ranged in size from Caudipteryx, which was the size of a turkey, to the 8 metre long, 1.4 ton Gigantoraptor. The group (along with all maniraptoran dinosaurs) is close to the ancestry of birds. Analyses like those of Maryanska et al (2002) and Osmólska et al. (2004) suggest that they may represent primitive flightless birds. The most complete oviraptorosaur specimens have been found in Asia. The North American oviraptorosaur record is sparse.The earliest and most basal ("primitive") known oviraptorosaurs are Ningyuansaurus wangi, Protarchaeopteryx robusta and Incisivosaurus gauthieri, both from the lower Yixian Formation of China, dating to about 125 million years ago during the Aptian age of the early Cretaceous period. A tiny neck vertebra reported from the Wadhurst Clay Formation of England shares some features in common with oviraptorosaurs, and may represent an earlier occurrence of this group (at about 140 million years ago).

Pennaraptora

Pennaraptora (Latin penna "bird feather" + raptor "thief", from rapere "snatch"; a feathered bird-like predator) is a clade defined as the most recent common ancestor of Oviraptor philoceratops, Deinonychus antirrhopus, and Passer domesticus (the house sparrow), and all descendants thereof, by Foth et al., 2014. The earliest known definitive member of this clade is Anchiornis, from the late Jurassic period of China, about 160 million years ago.

The clade "Aviremigia" was conditionally proposed along with several other apomorphy-based clades relating to birds by Jacques Gauthier and Kevin de Queiroz in a 2001 paper. Their proposed definition for the group was "the clade stemming from the first panavian with ... remiges and rectrices, that is, enlarged, stiff-shafted, closed-vaned (= barbules bearing hooked distal pennulae), pennaceous feathers arising from the distal forelimbs and tail".

Red Beds of Hermiin Tsav

The Red Beds of Hermiin Tsav is a geological formation in Mongolia whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.

Wulatelong

Wulatelong is an extinct genus of basal oviraptorid dinosaur known from the Late Cretaceous Wulansuhai Formation (Campanian stage) of Bayan Mandahu, Linhe District of Inner Mongolia, northern China. It contains a single species, Wulatelong gobiensis.

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