|Holotype skeleton of Tongtianlong limosus|
|Genus:||† Tongtianlong |
Lü et al., 2016
Lü et al., 2016
Tongtianlong (meaning "Tongtianyan dragon") is a genus of oviraptorid theropod dinosaurs that lived in the late Maastrichtian epoch of the late Cretaceous period. It contains one species, T. limosus.
Tongtianlong was a sheep-sized member of the oviraptorids, a group of omnivorous, feathered, bird-like theropods.The describers of Tongtianlong recognized that it possessed a set of distinctive characteristics that differentiated it both from other oviraptorosaurs. In particular, unlike other oviraptorids, the crest of Tongtianlong was shaped like a dome, with its highest point just behind the eye socket; and the front edge of the toothless premaxilla, which would have supported its beak, was very rounded.
Additionally, there is a distinct ridge on the front margin of the parietal bone, wedged between the frontal bones; the shaft of the lacrimal bone, which is located in front of the eye socket, is wide, flattened, and plate-like seen from the side; the foramen magnum (a hole in the back of the skull) is smaller than the occipital condyle (the boss forming the skull-neck joint); there is no ridge on the bottom of the front lower jaws, which is also not strongly downturned; and the xiphoid process does not flare out from the sternum behind the ribs. Other characteristics of the skull separate Tongtianlong from its contemporaries; for instance, the nostril is situated much higher than the antorbital fenestra, a trait seen otherwise only in Nemegtomaia and Rinchenia .
The holotype of Tongtianlong, specimen number DYM-2013-8, was discovered during the construction of a new high school near Ganxian District in Jiangxi Province, China. The site where it was found is part of the Nanxiong Formation, which dates to the Maastrichtian epoch (although a more precise dating has not yet been conducted). The specimen is currently stored in the Dongyang Museum.While the exceptionally well-preserved specimen was likely originally complete, portions of the arms, right leg, and tail were destroyed by the TNT blasting which unearthed the fossil. Near the hip, a drill hole that was used to place TNT can be seen.
The skeleton was preserved in an unusual pose, with a raised head and splayed arms; while it is difficult to tell exactly what led to this pose, :通天岩) grotto and the suffix -long (Chinese :龍, "dragon"). "Tongtian" also is a Chinese phrase meaning "road to heaven". The specific name, limosus (the Latin word for "muddy"), refers to how the specimen was preserved in mudstone. It was first described and named by Lü Junchang, Chen Rongjun, Stephen L. Brusatte, et al.it has been speculatively suggested that the specimen died while it was trapped in mud and trying to free itself. The genus name of Tongtianlong combines a reference to the nearby Tongtianyan (Chinese
In 2016, Tongtianlong was found to be a member of the Oviraptoridae, as a close relative of Banji and Wulatelong . The results of the phylogenetic analysis conducted are partially reproduced below.
Tongtianlong is the sixth oviraptorid described from the Nanxiong Formation, after Banji , Ganzhousaurus , Jiangxisaurus , Nankangia , and Huanansaurus , in that order. Given the variation in size among these oviraptorids (for instance, Banji is much smaller than Tongtianlong), it is reasonable to hypothesize that some of them might be growth stages of others; however, it is more likely that they represent genuinely distinct animals, since juvenile oviraptorid specimens show that their anatomy does not change significantly with age.
The describers of Tongtianlong suggested that this diversity is indicative of an evolutionary radiation of oviraptorids that occurred just prior to the Cretaceous–Paleogene extinction event.However, the possibility that these species come from different points in time cannot be excluded, due to a lack of study on the stratigraphy and age of the Nanxiong Formation.
Oviraptor is a genus of oviraptorid dinosaur that lived in Asia during the Late Cretaceous period. The first remains were collected from the Djadokhta Formation of Mongolia in 1923 during a paleontological expedition led by Roy Chapman Andrews, and in the following year the genus and type species Oviraptor philoceratops were named by Henry Fairfield Osborn. The genus name refers to the initial thought of egg-stealing habits, and the specific name was intended to reinforce this view indicating a preference over ceratopsian eggs. Despite the fact that numerous specimens have been referred to the genus, Oviraptor is only known from a single partial skeleton regarded as the holotype, as well as a nest of about fifteen eggs and several small fragments from a juvenile.
Byronosaurus is a genus of troodontid dinosaur from the Late Cretaceous Period of Mongolia.
Alioramus is a genus of tyrannosaurid theropod dinosaurs from the Late Cretaceous period of Asia. It currently contains two species. The type species, A. remotus is known from a partial skull and three foot bones recovered from the Mongolian Nemegt Formation, which was deposited in a humid floodplain about 70 million years ago. These remains were named and described by Soviet paleontologist Sergei Kurzanov in 1976. A second species, A. altai, known from a much more complete skeleton, was named and described by Stephen L. Brusatte and colleagues in 2009. Its relationships to other tyrannosaurid genera are unclear, with some evidence supporting a hypothesis that Alioramus is closely related to the contemporary species Tarbosaurus bataar.
Conchoraptor is a genus of oviraptorid dinosaur from the late Cretaceous Period of what is now Asia.
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Sinovenator is a genus of troodontid dinosaur from China. It is from the early Cretaceous Period.
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.
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Banji is an extinct genus of oviraptorid dinosaur that lived approximately 66 million years ago during the later part of the Cretaceous Period in what is now China. It was a small, lightly-built, ground-dwelling, bipedal carnivore, that was an estimated 65 cm (2.1 ft) long, as a juvenile.
The Nanxiong Formation is a Late Cretaceous geologic formation in Guangdong Province. Dinosaur remains are among the fossils that have been recovered from the formation.
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Yulong is an extinct genus of derived oviraptorid theropod dinosaur known from the Late Cretaceous Qiupa Formation of Henan Province, central China. It contains a single species, Yulong mini. It is known from many juvenile specimens that represent some of the smallest known oviraptorids.
Ganzhousaurus is an extinct genus of oviraptorine oviraptorid dinosaur known from the Late Cretaceous Nanxiong Formation of Nankang County, Ganzhou City of Jiangxi Province, southern China. It was found in a Maastrichtian deposit and contains a single species, Ganzhousaurus nankangensis. It is distinguished by a combination of primitive and derived features.
Jiangxisaurus is an extinct genus of oviraptorid theropod dinosaur from the Late Cretaceous Nanxiong Formation of southern China. It was similar to Heyuannia, but with more strongly curved anterior claws and a thinner, frailer mandible. This find is paleontologically significant because it contributes to current knowledge about the paleogeographical distribution of oviraptorids in southern China. It was most likely a herbivorus animal along with its close relatives Nankangia and Ganzhousaurus.
Nankangia is an extinct genus of caenagnathoid oviraptorosaurian dinosaur known from the Upper Cretaceous Nanxiong Formation of Nankang County, Ganzhou City of Jiangxi Province, southeastern China. It contains a single species, Nankangia jiangxiensis. N. jiangxiensis coexisted with at least four other caenagnathoids, including an unnamed oviraptorid, Banji long, Ganzhousaurus nankangensis and Jiangxisaurus ganzhouensis. The relatively short dentary and non-downturned mandibular symphysis of Nankangia suggest that it may have been more herbivorous than carnivorous. Its diet consisting of leaves and seeds.
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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.
Corythoraptor is a genus of oviraptorid dinosaur from the late Maastrichtian Nanxiong Formation of South China. It contains one species, C. jacobsi, known from a single well-preserved skeleton, and named after paleontologist Louis L. Jacobs. It bears a tall crest similar to that of the modern cassowary, and possibly had a similar functionality of display and resonance to detect lower-frequency sounds. Like other oviraptorids, the bones of Corythoraptor were heavily pneumatized with many air pockets. Microanalysis of the bones indicates seasonal growth spurts, and the type specimen probably died at the age of 6 or 7, meaning growth continued into at least the 8th year of development. The type specimen reached 1.6 m in length. Oviraptorids may have predominantly inhabited arid environments and ate xerophytic (drought-resistant) plants, nuts, and seeds. However, Corythoraptor coexisted with six other oviraptorid genera, and they may have all eaten different foods.
Lü Junchang was a Chinese palaeontologist and professor at the Institute of Geology, Chinese Academy of Geological Sciences. An expert on Mesozoic reptiles, he described and named dozens of dinosaur and pterosaur taxa including Tongtianlong, Qianzhousaurus, Heyuannia, Gannansaurus, Yunnanosaurus youngi, and Darwinopterus.