Ruixinia

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Ruixinia
Temporal range: Early Cretaceous (Barremian), ~125  Ma
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Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Sauropodomorpha
Clade: Sauropoda
Clade: Macronaria
Clade: Somphospondyli
Genus: Ruixinia
Mo et al., 2022
Species:
R. zhangi
Binomial name
Ruixinia zhangi
Mo et al., 2022

Ruixinia is an extinct genus of somphospondylan titanosauriform dinosaur from the Early Cretaceous (Barremian) Yixian Formation of China. The genus contains a single species, Ruixinia zhangi. The Ruixinia holotype is a partial articulated skeleton with the most complete series of caudal vertebrae known from any Asian titanosauriform. [1]

Contents

Discovery and naming

The Ruixinia holotype specimen, ELDM EL-J009, was found in sediments of the Yixian Formation in Beipiao, Liaoning Province, northeastern China. This locality is dated to the Barremian age of the Early Cretaceous period. The fossil material consists of a partial articulated skeleton including cervical, dorsal, and sacral vertebrae, caudal vertebrae and associated chevrons, dorsal ribs, and a left ilium, pubis, femur, tibia, astragalus, metatarsal V, and possible pedal phalanx. At the time of its description, the fossil material was still partially embedded in matrix, with only the left side of the bones prepared. [1]

In 2022, Ruixinia zhangi was described as a new genus and species of titanosauriform dinosaurs by Jinyou Mo, Feimin Ma, Yilun Yu, and Xing Xu. The binomial honors Ruixin Zhang, a contributor to the Erlianhaote Dinosaur Museum. [1]

Description

Ruixinia was a mid-sized sauropod, with an estimated length of approximately 12 meters. [1]

The neck of Ruixinia was over 4 meters long and consisted of at least 15 cervical vertebrae. Such a high number of cervical vertebrae is similar to Dongbeititan , Euhelopus , and Mamenchisaurus . [1]

The tail of Ruixinia contained at least 52 vertebrae. The last few vertebrae were fused together, an unusual trait in sauropods otherwise only known to occur in some Jurassic Asian sauropods such as Shunosaurus and Mamenchisaurus. However, the structure of the fused vertebrae differs between the three taxa. In Ruxinia, the fused vertebrae form a rodlike structure. [1]

The chevrons are distinctive, particularly that of the 20th caudal vertebra, which has a pentagonal shape. [1]

Classification

Mo et al. (2022) recovered Ruxinia to be a basal titanosaur, placed as the sister taxon of a clade containing Daxiatitan and Xianshanosaurus . [1] However, both Daxiatitan and Xianshanosaurus have also been suggested to have affinities with mamenchisaurids, [2] and Mo et al. noted several similarities between Ruixinia and Mamenchisaurus. Ruixinia was not found to be closely related to either of its contemporaries, Dongbeititan or Liaoningotitan . The cladogram below displays the results of the phylogenetic analyses of Mo et al. (2022). [1]

Titanosauriformes

Brachiosauridae

Somphospondyli

Huanghetitan spp.

Ligabuesaurus

Dongbeititan

Savannasaurus

Chubutisaurus

Angolatitan

Europatitan

Tastavinsaurus

Liubangosaurus

Euhelopodidae

Jiangshanosaurus

Titanosauria

Tambatitanis

Huabeisaurus

Dongyangosaurus

Andesaurus

Mongolosaurus

Vahiny

Jainosaurus

Ruyangosaurus

Ruixinia

Xianshanosaurus

Daxiatitan

Rinconsaurus

Muyelensaurus

Mendozasaurus

Argentinosaurus

Futalognkosaurus

Puertasaurus

Patagotitan

Notocolossus

Lithostrotia

Paleoecology

Ruixinia is a member of the Jehol Biota. Two other sauropod genera, Dongbeititan and Liaoningotitan, are also known from the Jehol Biota. [1]

Related Research Articles

<i>Mamenchisaurus</i> Sauropod dinosaur genus from Late Jurassic-Early Cretaceous Period

Mamenchisaurus is a genus of sauropod dinosaur known for their remarkably long necks which made up nearly half the total body length. Numerous species have been assigned to the genus; however, many of these might be questionable. Fossils have been found in the Sichuan Basin and Yunnan Province in China. Several species are from the Upper Shaximiao Formation whose geologic age is uncertain. However, evidence suggests that this be no earlier than the Oxfordian stage of the Late Jurassic. M. sinocanadorum dates to the Oxfordian stage and M. anyuensis to the Aptian stage of the Early Cretaceous around 114.4 mya. Most species were medium to large size sauropods, around 15 to 26 meters in length and possibly up to 35 meters (115 ft) based on two undescribed vertebrae.

<i>Beipiaosaurus</i> Extinct genus of dinosaurs

Beipiaosaurus is a genus of therizinosauroid theropod dinosaurs that lived in Asia during the Early Cretaceous in the Yixian Formation. The first remains were found in 1996 and formally described in 1999. Before the discovery of Yutyrannus, Beipiaosaurus were among the heaviest dinosaurs known from direct evidence to be feathered. Beipiaosaurus is known from three reported specimens. Numerous impressions of feather structures were preserved that allowed researchers to determine the feathering color which, turned out to be brownish.

<i>Euhelopus</i> Extinct genus of dinosaurs

Euhelopus is a genus of sauropod dinosaur that lived between 145 and 133 million years ago during the Berriasian and Valanginian stages of the Early Cretaceous in what is now Shandong Province in China. It was a large quadrupedal herbivore. Like sauropods such as brachiosaurs and titanosaurs, Euhelopus had longer forelegs than hind legs. This discovery was paleontologically significant because it represented the first dinosaur scientifically investigated from China: seen in 1913, rediscovered in 1922, and excavated in 1923 and studied by T'an during the same year. Unlike most sauropod specimens, it has a relatively complete skull.

<i>Huabeisaurus</i> Extinct genus of dinosaurs

Huabeisaurus was a genus of dinosaur from the Late Cretaceous. It was a sauropod which lived in what is present-day northern China. The type species, Huabeisaurus allocotus, was first described by Pang Qiqing and Cheng Zhengwu in 2000. Huabeisaurus is known from numerous remains found in the 1990s, which include teeth, partial limbs and vertebrae. Due to its relative completeness, Huabeisaurus represents a significant taxon for understanding sauropod evolution in Asia. Huabeisaurus comes from Kangdailiang and Houyu, Zhaojiagou Town, Tianzhen County, Shanxi province, China. The holotype was found in the unnamed upper member of the Huiquanpu Formation, which is Late Cretaceous (?Cenomanian–?Campanian) in age based on ostracods, charophytes, and fission-track dating.

Daanosaurus was a genus of dinosaur. It was a sauropod which lived during the Late Jurassic. It lived in what is now China, and was similar to Bellusaurus.

<i>Sinusonasus</i> Extinct genus of dinosaurs

Sinusonasus is a genus of dinosaurs from the Early Cretaceous Period, recovered from the Yixian Formation. It lived in what is now the Liaoning Province of China. Sinusonasus was a theropod, specifically a troodontid dinosaur.

<i>Liaoningosaurus</i> Extinct genus of dinosaurs

Liaoningosaurus is an unusual genus of basal ankylosaurid dinosaur from the Liaoning Province, China that lived during the Early Cretaceous in what is now the Yixian and Jiufotang Formation. The type and only species, Liaoningosaurus paradoxus, is known from more than 20 specimens, with some representing juveniles. It was named in 2001 by Xu, Wang and You.

Fusuisaurus is a genus of sauropod dinosaur from the Early Cretaceous of China. Fragmentary postcranial remains of this animal have been discovered in 2001 in the Napai Formation of Guangxi, China and consist of the left ilium, left pubis, anterior caudals, most of the dorsal ribs and distal end of the left femur. This sauropod has been described as a basal titanosauriform.

<i>Dongbeititan</i> Extinct genus of dinosaurs

Dongbeititan is a genus of sauropod dinosaur from the Early Cretaceous-age Yixian Formation of Beipiao, Liaoning, China. It is based on holotype DNHM D2867, a partial postcranial skeleton including bones from the limbs, shoulder and pelvic girdles, and vertebrae, which was described in 2007. Its describers suggested it was as a basal titanosauriform, not as derived as Gobititan or Jiutaisaurus, but more derived than Euhelopus, Fusuisaurus, and Huanghetitan. The type species is D. dongi, and it is the first named sauropod from the Yixian Formation, which is part of the well-known Jehol Group. The genus name refers to the region Dongbei and to Greek titan, "giant". The specific name honours the Chinese paleontologist Dong Zhiming. Like other sauropods, Dongbeititan would have been a large quadrupedal herbivore.

<i>Dongyangosaurus</i> Extinct genus of dinosaurs

Dongyangosaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous. The only species is Dongyangosaurus sinensis, from which only a single fragmentary skeleton is known, coming from the Zhejiang province of eastern China. It was described and named by Lü Junchang and colleagues. Like other sauropods, Dongyangosaurus would have been a large quadrupedal herbivore.

<i>Daxiatitan</i> Extinct genus of dinosaurs

Daxiatitan is a genus of sauropod dinosaur known from the Lower Cretaceous of Gansu, China. Its type and only species is Daxiatitan binglingi. It is known from a single partial skeleton consisting of most of the neck and back vertebrae, two tail vertebrae, a shoulder blade, and a thigh bone. At the time of its discovery in 2008, Daxiatitan was regarded as potentially the largest known dinosaur from China.

<i>Ruyangosaurus</i> Extinct genus of dinosaurs

Ruyangosaurus is a genus of titanosauriform sauropod dinosaur recovered from the Early Cretaceous Haoling Formation of China. The type species is R. giganteus, described in 2009 by Lü Junchang et al.

<i>Tianyuraptor</i> Extinct genus of dinosaurs

Tianyuraptor is a genus of short-armed dromaeosaurid dinosaur that lived during the Early Cretaceous, about 122 million years ago. Its remains have been found in western Liaoning, China. It was similar to other dromaeosaurids found in Liaoning, with the exception of being somewhat more primitive. The type specimen, formally named in 2009, shows features not seen in previously known Northern Hemisphere (Laurasian) dromaeosaurids, but present in Southern Hemisphere (Gondwanan) species and early birds. Because of this, the scientists who first studied Tianyuraptor described it as a "transitional species", bridging the gap between northern and southern types of dromaeosaurid. Tianyuraptor also differs from previously known dromaeosaurids in that it possesses a relatively small furcula ("wishbone"), and unusually short forelimbs.

<i>Xianshanosaurus</i> Extinct genus of dinosaurs

Xianshanosaurus is a genus of sauropod dinosaur from the Early Cretaceous (Aptian-Albian) of the Ruyang Basin in Henan Province, China. Its type and only species is Xianshanosaurus shijiagouensis. It was described in 2009 by a team of paleontologists led by Lü Junchang. Xianshanosaurus may be a titanosaur, and Daxiatitan may be its closest relative, but its evolutionary relationships remain controversial.

Liubangosaurus is a genus of sauropod dinosaur that lived during the Early Cretaceous in what is now China. The type and only species is Liubangosaurus hei, first described by Mo Jinyou, Xu Xing and Eric Buffetaut in 2010. Liubangosaurus is known from the holotype NHMG8152, five nearly complete and articulated middle-caudal dorsal vertebrae that were collected from the Xinlong Formation in Fusui County, Guangxi Province. Mo et al. (2010) found that Liubangosaurus belonged to the clade Eusauropoda.

<i>Yongjinglong</i> Extinct genus of dinosaurs

Yongjinglong is an extinct genus of titanosauriform sauropod dinosaur known from the Early Cretaceous of Lanzhou-Minhe Basin of Gansu Province, China. It contains a single species, Yongjinglong datangi.

<i>Liaoningvenator</i> Extinct genus of dinosaurs

Liaoningvenator is a genus of troodontid theropod dinosaur from the Early Cretaceous of China. It contains a single species, L. curriei, named after paleontologist Phillip J. Currie in 2017 by Shen Cai-Zhi and colleagues from an articulated, nearly complete skeleton, one of the most complete troodontid specimens known. Shen and colleagues found indicative traits that placed Liaoningvenator within the Troodontidae. These traits included its numerous, small, and closely packed teeth, as well as the vertebrae towards the end of its tail having shallow grooves in place of neural spines on their top surfaces.

Liaoningotitan is a genus of titanosauriform sauropod from the Early Cretaceous (Barremian) Yixian Formation in Liaoning, China.

<i>Lingwulong</i> Dicraeosaurid dinosaur genus from Mid Jurassic China

Lingwulong is a genus of dicraeosaurid sauropod dinosaur from the Middle Jurassic of what is now Lingwu, Yinchuan, Ningxia, China. The type and only species is L. shenqi, known from several partial skeletons. It is the earliest-aged neosauropod ever discovered, as well as the only definite diplodocoid from east Asia.

Fushanosaurus is a genus of sauropod dinosaur from the Shishugou Formation from Xinjiang Province in China. The type and only species is Fushanosaurus qitaiensis. It is solely known from the holotype specimen FH000101, a complete right femur.

References

  1. 1 2 3 4 5 6 7 8 9 10 Mo, Jinyou; Ma, Feimin; Yu, Yilun; Xu, Xing (2022-12-09). "A New Titanosauriform Sauropod with An Unusual Tail from the Lower Cretaceous of Northeastern China". Cretaceous Research. 144: 105449. doi:10.1016/j.cretres.2022.105449. ISSN   0195-6671. S2CID   254524890.
  2. Moore, Andrew J.; Upchurch, Paul; Barrett, Paul M.; Clark, James M.; Xu, Xing (2020-05-28). "Osteology of Klamelisaurus gobiensis (Dinosauria, Eusauropoda) and the evolutionary history of Middle–Late Jurassic Chinese sauropods". Journal of Systematic Palaeontology. 18 (16): 1299–1393. doi:10.1080/14772019.2020.1759706. ISSN   1477-2019. S2CID   219749618.