Thistimeline of oviraptorosaur researchis a chronological listing of events in thehistoryof paleontology focused on theoviraptorosaurs,a group ofbeaked,bird-liketheropoddinosaurs.The earlyhistoryof oviraptorosaur paleontology is characterized bytaxonomicconfusion due to the unusual characteristics of these dinosaurs. When initially described in1924Oviraptoritself was thought to be a member of theOrnithomimidae,popularly known as the "ostrich"dinosaurs, because both taxa share toothless beaks.[1]Earlycaenagnathidoviraptorosaur discoveries likeCaenagnathusitself were also incorrectly classified at the time, having been misidentified as birds.[1]
Thehypothesisthat caenagnathids were birds was questioned as early as1956byRomer,but not corrected untilOsmolskaformally reclassified them as dinosaurs in1976.Meanwhile, the classification ofOviraptoras an ornithomimid persisted unquestioned by researchers like Romer andSteel[disambiguation needed]until the early1970swhenDale Russellargued against the idea in1972.In 1976 when Osmolska recognizedOviraptor's relationship with the Caenagnathids, she also recognized that it was not an ornithomimid and reclassified it as a member of the former family.[1]However, that same yearRinchen Barsboldargued thatOviraptorbelonged to a distinct family he named theOviraptoridae[1]and he also formally named the Oviraptorosauria later in the same year.[2]
Like their classification, thepaleobiologyof oviraptorosaurs has been subject to controversy and reinterpretation. The first scientifically documentedOviraptorskeleton was found lying on a nest ofeggs.Because its powerfulparrot-like beak appeared well-adapted to crushing hard food items and the eggs were thought to belonged to theneoceratopsianProtoceratops,oviraptorosaurs were thought to be nest-raiders that preyed on the eggs of other dinosaurs. In the1980s,Barsbold proposed that oviraptorosaurs used their beaks to crackmolluskshells as well. In1993,Currieand colleagues hypothesized that smallvertebrateprey may have also been part of the oviraptorosaur diet. Not long after,fossil embryonic remainscast doubt on the popular reconstruction of oviraptorosaurs as egg thieves when it was discovered that the "Protoceratops"eggs thatOviraptorwas thought to be "stealing" actually belonged toOviraptoritself. The discovery of additionalOviraptorpreserved on top of nests in lifelikebroodingposture firmly established that oviraptorosaurs had been "framed" as egg thieves and were actually caring parentsincubatingtheir own nests.[3]
Osborn described the new genus and speciesOviraptor philoceratops.[2]He classified it as an ornithomimid because it didn't have any teeth in its jaws[1]and interpreted the genus as being adapted to a diet of eggs.[3]Since a specimen was found preserved on top of a nest of eggs presumed to belong to Protoceratops, Osborn thought that it was smothered by a sandstorm while in the act of raiding the nest.[3]
Romer followed Osborn's original classification ofOviraptoras an ornithomimid. He also observed that caenagnathids had reptilian characteristics and may have been coelurosaurs.[1]
Steel followed Osborn's original classification ofOviraptoras an ornithomimid.[1]He also questioned the avian status of caenagnathids and proposed that they might actually be coelurosaurs instead.[1]
Known skeletal material ofAjancingenia,formerly "Ingenia"
Barsbold described the new genus and speciesIngenia yanshini.[4]He also named the subfamily Ingeniinae[4]and classified the family Caenagnathidae in the Oviraptorosauria.[1]
Currie and others built a case for interpreting oviraptorosaurs as egg-eaters who supplemented their diet with small prey. They noted supporting traits like the animals' ability to give a "powerful nipping bite" with the front of its beak. Oviraptorosaurs also had tooth-like projections from the roof of the mouth, which resemble similar adaptations in modern egg-eating mammals.NestingCitipatispecimen nicknamed "Big Auntie"The orientation of the throat on the underside of the jaw is also consistent with this reconstruction of oviraptorosaur paleoecology.[3]
Russell and Dong argued that the Maniraptora (which includes Oviraptorosauria) was a polyphyletic assemblage of unrelated groups. Instead they classified the traditional oviraptorosaurs with the ornithomimids, therizinosauroids, and troodontids in a new, greatly expanded Oviraptorosauria.[5]
Norell and others reported the discovery of a tiny theropod skeleton in an oviraptorid nest. They suggested this find was evidence that oviraptorosaur hunted tiny game. They also noted that the supposedProtoceratopseggs of the Central Asiatic Expeditions actually preserved the embryonic remains of oviraptorosaurs.[3]
Currie reported the presence of nests of large eggs more than 40 centimetres (16 in) long in China. Oviraptorosaurs would come to be considered possible candidates for the egg layers.[3]FossilizedCitipatiegg with preserved embryo
Dong and Currie reported the discovery of an oviraptorid from the Djadokhta Formation of northern China preserved on top of a nest of eggs. This overturned more than 60 years of interpreting theOviraptorof the Central Asiatic Expeditions as a rapacious egg-thief in favor of it likely being a faithful mother at her nest. The researchers reconstructed the way mother oviraptorosaurs built their nests. The standing mother would lay a pair of eggs and bury them by hand. Then she would turn and repeat the process until she had made a ring of egg-pairs completely around herself. Since by then the area where she was standing would be higher than the eggs, she would repeat the process with another ring of egg-pairs as a second layer. This process would gradually build an egg mound containing as many as 30 eggs in up to three layers.[3]
Sues published a critical review of earlier interpretations of the oviraptorosaurs' evolutionary relationships and formulated the clade's firstsynapomorphy-based diagnosis. He also performed a cladistic analysis and found oviraptorosaurs to be the sister group of the therizinosaurs.[6]
Sereno regarded oviraptorosaurs as maniraptorans and found them to be the sister group of Paraves (which includes deinonychosaurs and birds) in a cladistic analysis.[6]
Padian and others published a cladistic definition for Oviraptorsauris for the first time; all taxa closer toOviraptorthan to birds.[6]
Barsbold described the new genusRincheniafor the speciesOviraptor mongoliensis.[2]Barsbold credited Currie and Padian for defining Oviraptorosauria as the Oviraptoridae and all taxa closer toOviraptor.[6]
Sereno regarded oviraptorosaurs as maniraptorans and found them to be the sister group of Paraves (which includes deinonychosaurs and birds) in a cladistic analysis.[6]He defined oviraptorosaurs as all maniraptorans closer toOviraptorthan to Neornithes.[6]
Currie, Norell, and Ji described the new genus and speciesCaudipteryx zoui.[2]
Ji and others reported the presence of gastroliths inCaudipteryx.These are evidence for an herbivorous diet.[3]
Makovicky and Sues considered oviraptorosaurs to be the sister group of the therizinosaurs.[6]
Sereno foundCaudipteryxto be a basal oviraptorosaur. He also erected the clade Caenagnathoidea for the caenagnathids and oviraptorids.[6]
Elzanowski performed a cladistic analysis and found a group consisting of oviraptorosaurs, ornithomimosaurs and therizinosaurs were more closely related to birds than deinonychosaurs. No other cladistic study in the history of dinosaur research had come up with this result.[6]
Padian and others changed the definition of Oviraptorosauria from a stem-based clade to a node-based one. They defined the oviraptorosaurs as "OviraptorandChirostenotes(=Caenagnathus) and all the descendants of their most recent common ancestor. "[6]
Clark and others observed that oviraptorosaurs are among the most common dinosaurs found at Ukhaa Tolgod in Mongolia.[3]They reported further specimens preserved on nests in brooding position. They suggested contrary to Dong and Currie's 1996 reconstruction of oviraptorosaur nest-building behavior that the animals may have constructed their nests by maneuvering the eggs into position by hand. However, this explanation is less parsimonious and has less evidentiary support, so it never gained favor among paleontologists.[3]
Kevin Padian,Ji QiangandJi Shu-anpublished a review of knownfeathered dinosaursand their implications for theorigin of flight.[8]The authors observe that many aspects of the distribution of feather homologues meet the expectations of earlier phylogenetic hypotheses, including a gradual transition from primitive filaments inSinosauropteryxto the shared filaments and "rudimentary" true feathers inCaudipteryxandProtarchaeopteryx,to flight feathers inArchaeopteryx.[9]The team speculates that the plumulaceous feathers inCauditeryxandProtarchaeopteryxmay have originated as tufts ofSinosauropteryx-style filaments, the shafts of which possibly formed by the consolidation of individual filaments.[10]The parallel nature of the barbs inCaudipteryxandProtarcheopteryxsuggest the existence ofbarbules.[11]This suggests that barbules, which are necessary for flight-worthy wings, evolved prior to flight.[11]
Cladogram of feathered dinosaurs from Padian et al. 2001
2002?Teresa Maryańskaand others confirmed Sereno's finding thatCaudipteryxwas an oviraptorosaur. They also foundAvimimusto be an oviraptorosaur as well.[6]
Xu and others described the new genus and speciesIncisivosaurus gauthieri.[2]Their research supported recent findings thatCaudipteryxandAvimimuswere oviraptorosaurs.[6]
Maryanska and others performed a cladistic analysis that found oviraptorosaurs to be avialans.[6]
Zelenitsky and others studied the shape and shell histology of the large fossil eggs reported from China by Currie in 1996 and concluded that they may have been laid by oviraptorosaurs. Given their large size, this implied that giant oviraptorosaurs remained to be discovered.[3]
^G.F. Funston; S.E. Mendonca; P.J. Currie; R. Barsbold (2018). "Oviraptorosaur anatomy, diversity and ecology in the Nemegt Basin".Palaeogeography, Palaeoclimatology, Palaeoecology.494:101–120.Bibcode:2018PPP...494..101F.doi:10.1016/j.palaeo.2017.10.023.
Easter, J. (2013). "A new name for the oviraptorid dinosaur"Ingenia" yanshini(Barsbold, 1981; preoccupied by Gerlach, 1957) ".Zootaxa.3737(2):184–190.doi:10.11646/zootaxa.3737.2.6.PMID25112747.
Ji Qiang; Lü Jun-Chang; Wei Xue-Fang; Wang Xu-Ri (2012). "A new oviraptorosaur from the Yixian Formation of Jianchang, Western Liaoning Province, China".Geological Bulletin of China.31(12):2102–2107.
Longrich, N. R.; Barnes, K.; Clark, S.; Millar, L. (2013). "Caenagnathidae from the Upper Campanian Aguja Formation of West Texas, and a Revision of the Caenagnathinae".Bulletin of the Peabody Museum of Natural History.54:23–49.doi:10.3374/014.054.0102.S2CID128444961.
Lü, J.; Tomida, Y.; Azuma, Y.; Dong, Z.; Lee, Y.-N. (2004). "New oviraptorid dinosaur (Dinosauria: Oviraptorosauria) from theNemegt Formationof southwestern Mongolia ".Bulletin of the National Science Museum, Tokyo, Series C.30:95–130.
Lu, J.; Zhang, B.-K. (2005). "A new oviraptorid (Theropoda: Oviraptorosauria) from the Upper Cretaceous of the Nanxiong Basin, Guangdong Province of southern China".Acta Palaeontologica Sinica.44(3):412–422.
Osmólska, Halszka; Currie, Philip J.; Barsbold, Rinchen (2004). "Oviraptorosauria". In Weishampel, D. B.; Dodson, P.; Osmolska, H. (eds.).The Dinosauria(2 ed.). Berkeley: University of California Press. pp.165–193.ISBN978-0-520-25408-4.
Padian, K.; Ji, Qiang; Ji, Shu-An (2001). "Feathered dinosaurs and origin of flight". In Tanke, Darren H; Carpenter, Kenneth (eds.).Mesozoic Vertebrate Life.Indiana University Press. pp.117–135.ISBN978-0-253-33907-2.
Varrichio, D. J. (2001). "Late Cretaceous oviraptorosaur (Theropoda) dinosaurs from Montana". In Tanke, D. H.; Carpenter, K. (eds.).Mesozoic Vertebrate Life.Life of the Past. Indiana University Press. pp.42–57.
Wang, S.; Sun, C.; Sullivan, C.; Xu, X. (2013). "A new oviraptorid (Dinosauria: Theropoda) from the Upper Cretaceous of southern China".Zootaxa.3640(2):242–257.doi:10.11646/zootaxa.3640.2.7.PMID26000415.
Wei Xuefang, Pu Hanyong, Xu Li, Liu Di and Lü Junchang (2013). "A New Oviraptorid Dinosaur (Theropoda: Oviraptorosauria) from the Late Cretaceous of Jiangxi Province, Southern China".Acta Geologica Sinica (English Edition).87(4):899–904.doi:10.1111/1755-6724.12098.S2CID129797420.{{cite journal}}:CS1 maint: multiple names: authors list (link)
Xu, X.; Han, F.-L. (2010). "A new oviraptorid dinosaur (Theropoda: Oviraptorosauria) from the Upper Cretaceous of China".Vertebrata PalAsiatica.48(1):11–18.
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