A Late Cretaceous diversification of Asian oviraptorid dinosaurs: evidence from a new species preserved in an unusual posture

Abstract

Oviraptorosaurs are a bizarre group of bird-like theropod dinosaurs, the derived forms of which have shortened, toothless skulls, and which diverged from close relatives by developing peculiar feeding adaptations. Although once among the most mysterious of dinosaurs, oviraptorosaurs are becoming better understood with the discovery of many new fossils in Asia and North America. The Ganzhou area of southern China is emerging as a hotspot of oviraptorosaur discoveries, as over the past half decade five new monotypic genera have been found in the latest Cretaceous (Maastrichtian) deposits of this region. We here report a sixth diagnostic oviraptorosaur from Ganzhou, Tongtianlong limosus gen. et sp. nov., represented by a remarkably well-preserved specimen in an unusual splayed-limb and raised-head posture. Tongtianlong is a derived oviraptorid oviraptorosaur, differentiated from other species by its unique dome-like skull roof, highly convex premaxilla, and other features of the skull. The large number of oviraptorosaurs from Ganzhou, which often differ in cranial morphologies related to feeding, document an evolutionary radiation of these dinosaurs during the very latest Cretaceous of Asia, which helped establish one of the last diverse dinosaur faunas before the end-Cretaceous extinction.

δ18O‐derived incubation temperatures of oviraptorosaur eggs

“…, ) and Tongtianlong limosus (Lü et al . ). According to Equation , the body mass of the oviraptorosaurs that laid the Jiangxi eggs ranged from about 36 kg to 140 kg (Table ), which is comparable to other estimates ranging from 20 kg to 75 kg for some of the Jiangxi taxa (Paul ).…”

High diversity of the Ganzhou Oviraptorid Fauna increased by a new “cassowary-like” crested species

“…Corythoraptor jacobsi differs from Tongtianlong limosus 9 in the skull morphology. The anteroventral corner of the external naris is far above a horizontal line tangent with the posterodorsal corner of the antorbital fenestra, and the skull is dome-like in Tongtianlong .…”

“…We conducted a phylogenetic analysis to investigate the taxonomic affinities of Corythoraptor within Oviraptorosauria, using the modified data matrix 9, 40 (see also Supplementary Information) of Lamanna et al . 41 .…”

“…In recent years, diverse oviraptorid-like eggs (and clutches) as well as oviraptorid skeletons that have been unearthed from the Upper Cretaceous deposits of Ganzhou, Jiangxi Province, southern China, have made the Ganzhou area one of the most productive oviraptorosaurian regions of the world. At present, six oviraptorosaurian dinosaurs have been named from Ganzhou, including Banji long 4 , Jiangxisaurus ganzhouensis 5 , Nankangi a jiangxiensis 6 , Ganzhousaurus nankangensis 7 , Huanansaurus ganzhouensis 8 , and Tongtianlong limosus 9 . All taxa are from the Upper Cretaceous Nanxiong Formation, comprising a distinct “Ganzhou Dinosaurian Fauna” 8 .…”

First North American occurrences ofQiupalong(Theropoda: Ornithomimidae) and the palaeobiogeography of derived ornithomimids

“…also represents the sixth ornithomimid taxon reported from the Dinosaur Park Formation. Although it may be suspected that not all of these taxa are distinct (e.g., Makovicky et al 2004), the taxonomic diversity of non-macropredaceous theropods such as ornithomimosaurs and oviraptorosaurs in the Late Cretaceous may have been greater than generally appreciated, with at least three genera of Caenagnathidae present in the Dinosaur Park Formation (Funston et al 2015), and seven genera of Oviraptoridae present in the Nanxiong Formation of southern China (Lü et al 2016). …”