Qianjiangsaurus

Last updated

Qianjiangsaurus
Temporal range: Late Cretaceous
Qianjiangsaurus changshengi.png
Life restoration
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Ornithischia
Clade: Neornithischia
Clade: Ornithopoda
Clade: Hadrosauriformes
Superfamily: Hadrosauroidea
Genus: Qianjiangsaurus
Dai et al., 2024
Species:
Q. changshengi
Binomial name
Qianjiangsaurus changshengi
Dai et al., 2024

Qianjiangsaurus (meaning "Qianjiang lizard") is an extinct genus of hadrosauroidean ornithopod dinosaurs from the Late Cretaceous Zhengyang Formation of China. The genus contains a single species, Q. changshengi, known from a partial skeleton. Qianjiangsaurus is one of the few hadrosauroids named from south China, and it indicates important fauna connections between similarly aged formations in Mongolia.

Contents

Discovery and naming

The Qianjiangsaurus holotype specimen, CLGRP V00016, was discovered by a paleontological expedition associated with the Chongqing Bureau of Geological and Mineral Resource Exploration and Development during the winter of 2022. The locality represents sediments of the Zhengyang Formation near Zhengyang area in Qianjiang District, Chongqing Municipality of southwest China. The specimen consists of a partial, somewhat articulated skeleton, comprising an incomplete mandible, four dorsal vertebrae, the sacrum, many caudal vertebrae and associated chevrons, most of the pelvic girdle, and several hindlimb bones. [1]

In 2024, Dai et al. described Qianjiangsaurus changshengi as a new genus and species of hadrosauroid dinosaurs based on these fossil remains. The generic name, Qianjiangsaurus, combines "Qianjiang"—the name of the district containing the type locality—with the Greek σαῦρος (sauros), meaning 'lizard'. The specific name, changshengi, Changsheng Wang, the discoverer of the Chongqing fossil locality. [1]

Nanningosaurus , a genus from the Nalong Basin of Guangxi, is the only other hadrosauroid currently named from south China. [1] [2]

Description

Size compared to a human Qianjiangsaurus Size Comparison.svg
Size compared to a human

The holotype of Qianjiangsaurus likely represents a mature adult individual. It is medium-sized in comparison to related taxa, at about 8 metres (26 ft) long. [1]

The prepubic process of the pubis is fan-shaped, with a length:height ratio of about 0.79, representing the single autapomorphy (unique derived trait) identified in the holotype. The unique combination of other characters includes a total of 30 dentary tooth positions with no more than five teeth per alveolus (tooth socket), a coronoid process at a right angle to the dentary, and seven fused vertebrae in the sacrum. While some of its plesiomorphic (ancestral) anatomical features confidently place it within the Hadrosauroidea, it still demonstrates apomorphic (derived) features of later-diverging members of the Hadrosauridae, placing it as a transitional form between the two groups. [1]

Classification

In their phylogenetic analyses, Dai et al. (2024) recovered Qianjiangsaurus as the sister taxon to the Mongolian Plesiohadros , [3] with these taxa as late-diverging members of the Hadrosauroidea outside of the Hadrosauridae. Their results are displayed in the cladogram below: [1]

Hadrosauriformes

Paleoecology

The discovery of Qianjiangsaurus provides further support for several faunal similarities between the Zhengyang Formation of China and the Djadokhta and Baruungoyot formations of Mongolia. These dinosaur parallels may indicate a faunal interchange between the two regions during the end of the Late Cretaceous, from the late Campanian–early Maastrichtian. While absolute dates have yet to be determined for the Zhengyang Formation, it was likely deposited during this time. [1]

Qianjiangsaurus is the first distinct dinosaur taxon to be named from the Zhengyang Formation. Fragmentary specimens belonging to unnamed titanosaurs and theropods (including tyrannosauroids and putative carnosaurs) have also been found. Since large-scale excavations had not occurred in the region until 2022, additional specimens—such as ornithomimosaurs, therizinosauroids, oviraptorosaurs as seen in coeval formations—may be found in the future. [1] [4] [5]

See also

Related Research Articles

<i>Shantungosaurus</i> Genus of ornithopod dinosaurs

Shantungosaurus is a genus of very large saurolophine hadrosaurid dinosaur found in the Late Cretaceous Wangshi Group of the Shandong Peninsula in China, containing a single species, Shantungosaurus giganteus. The stratigraphic interval of Shantungosaurus ranges from the top of the Xingezhuang Formation to the middle of the Hongtuya Formation, middle to late Campanian in age. Shantungosaurus is so far the largest hadrosauroid taxon in the world, with size estimates around 15–17 metres (49–56 ft) in length and 13–16 metric tons in body mass.

<i>Lophorhothon</i> Genus of dinosaur

Lophorhothon is a genus of hadrosauroid dinosaur from the Late Cretaceous of Alabama and North Carolina. It was the first genus of dinosaur discovered in Alabama, in the United States.

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

Arstanosaurus is a genus of hadrosauroid dinosaur from the Santonian-Campanian-age Upper Cretaceous Bostobe Formation, Kazakhstan. It has had a confusing history, being considered both a hadrosaurid and a ceratopsid, or both at the same time (chimeric).

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

Barsboldia is a genus of large hadrosaurid dinosaur from the early Maastrichtian Nemegt Formation of Ömnogöv', Mongolia. It is known from a partial vertebral column, partial pelvis, and some ribs.

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

Pararhabdodon is a genus of tsintaosaurin hadrosaurid dinosaur, from the Maastrichtian-age Upper Cretaceous Tremp Group of Spain. The first remains were discovered from the Sant Romà d’Abella fossil locality and assigned to the genus Rhabdodon, and later named as the distinct species Pararhabdodon isonensis in 1993. Known material includes assorted postcranial remains, mostly vertebrae, as well as maxillae from the skull. Specimens from other sites, including remains from France, a maxilla previously considered the distinct taxon Koutalisaurus kohlerorum, an additional maxilla from another locality, the material assigned to the genera Blasisaurus and Arenysaurus, and the extensive Basturs Poble bonebed have been considered at different times to belong to the species, but all of these assignments have more recently been questioned. It was one of the last non-avian dinosaurs known from the fossil record that went extinct during the Cretaceous-Paleogene extinction event.

<i>Gilmoreosaurus</i> Hadrosauroid dinosaur genus from the Late Cretaceous

Gilmoreosaurus is the name given to a genus of dinosaur from the Cretaceous of Asia. The type species is Gilmoreosaurus mongoliensis. It is believed to be a hadrosaur or iguanodont from the Iren Dabasu Formation of Inner Mongolia, dating to 96 Ma ago. Additional specimens have been described as distinct species, including G. atavus from the Khodzhakul Formation of Uzbekistan and G. arkhangelskyi from the Bissekty Formation. However, these are based on very fragmentary remains, and their classification is dubious. An additional species, G. kysylkumense is sometimes included, though it has also been referred to the related genus Bactrosaurus.

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

Probactrosaurus is an early herbivorous hadrosauroid iguanodont dinosaur. It lived in China during the Early Cretaceous period.

<i>Tethyshadros</i> Hadrosauroid dinosaur from Late Cretaceous Italy

Tethyshadros is a genus of hadrosauroid dinosaur from the Calcare di Aurisina of Trieste, Italy. The type and only species is T. insularis.

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

Willinakaqe is a dubious genus of saurolophine hadrosaurid dinosaur described based on fossils from the late Cretaceous of the Río Negro Province of southern Argentina.

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

Huehuecanauhtlus is a genus of hadrosauroid dinosaur known from the Late Cretaceous of Michoacán, western Mexico. It contains a single species, Huehuecanauhtlus tiquichensis.

<i>Latirhinus</i> Extinct genus of reptiles

Latirhinus is an extinct genus of lambeosaurine hadrosaurid dinosaur from the Late Cretaceous of Mexico. The type species, Latirhinus uitstlani, was named in 2012 on the basis of a partial skeleton from the Campanian-age Cerro del Pueblo Formation. The specific name uitstlani means "southern" in the Náhuatl language of Mexico, a reference to the species' southern occurrence in the Cretaceous landmass Laramidia.

<i>Yunganglong</i> Genus of dinosaurs

Yunganglong is an extinct genus of basal hadrosauroid dinosaur known from the early Late Cretaceous lower Zhumapu Formation of Zuoyun County, Shanxi Province of northeastern China. It contains a single species, Yunganglong datongensis.

Plesiohadros is an extinct genus of hadrosauroid dinosaur. It is known from a partial skeleton including the skull collected at Alag Teg locality, from the Campanian Alagteeg Formation of southern Mongolia. The type species is Plesiohadros djadokhtaensis.

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

Zhanghenglong is an extinct genus of herbivorous hadrosauroid iguanodont dinosaur known from the Late Cretaceous Majiacun Formation in Xixia County of Henan Province, China. It contains a single species, Zhanghenglong yangchengensis, represented by a disarticulated and partial cranium and postcranial skeleton.

<span class="mw-page-title-main">Timeline of hadrosaur research</span>

This timeline of hadrosaur research is a chronological listing of events in the history of paleontology focused on the hadrosauroids, a group of herbivorous ornithopod dinosaurs popularly known as the duck-billed dinosaurs. Scientific research on hadrosaurs began in the 1850s, when Joseph Leidy described the genera Thespesius and Trachodon based on scrappy fossils discovered in the western United States. Just two years later he published a description of the much better-preserved remains of an animal from New Jersey that he named Hadrosaurus.

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

Zuoyunlong is an extinct genus of herbivorous ornithischian dinosaur belonging to the Hadrosauroidea, that lived during the Late Cretaceous in the area of present China.

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

Bonapartesaurus is an extinct genus of herbivorous ornithopod dinosaur belonging to Hadrosauridae, which lived in the area of modern Argentina during the Campanian and Maastrichtian stages of the Late Cretaceous.

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

Adynomosaurus is a genus of lambeosaurine dinosaur from the Late Cretaceous of what is now Catalonia, Spain. First discovered in 2012, it was named in 2019 with the type and only species being Adynomosaurus arcanus. It is only known from scant material, but is distinguished from other hadrosaurs by its weakly developed shoulder blade which would have had underdeveloped musculature, which lends it its scientific name, partially from the Greek word for "weak". Its exact relationships with other hadrosaurs remain unresolved, with it not consistently being recovered as a relative of any other specific genera, though some studies have allied it with Tsintaosaurini or even found it outside of Hadrosauridae. It would have lived as part of a diverse coastal estuary ecosystem, made up of meandering rivers and mud flats. The discovery of Adynomosaurus adds to the very incomplete fossil record of hadrosaurid dinosaurs in the Late Cretaceous of Europe, and it fits into a picture of major ecological turnover that was occurring during the Maastrichtian stage in the region.

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

Gobihadros is a genus of basal hadrosauroid dinosaur that lived in Asia during the Late Cretaceous period in what is now the Bayan Shireh Formation (Cenomanian-Santonian). It contains only the type species Gobihadros mongoliensis. It has an estimated length of 7.5 m (25 ft).

References

  1. 1 2 3 4 5 6 7 8 Dai, Hui; Ma, Qingyu; Xiong, Can; Lin, Yu; Zeng, Hui; Tan, Chao; Wang, Jun; Zhang, Yuguang; Xing, Hai (2024-08-27). "A new late-diverging non-hadrosaurid hadrosauroid (Dinosauria: Ornithopoda) from southwest China: support for interchange of dinosaur faunas across East Asia during the Late Cretaceous". Cretaceous Research (in press): 105995. doi:10.1016/j.cretres.2024.105995. ISSN   0195-6671.
  2. Mo J.; Zhao Z.; Wang W.; Xu X. (2007). "The first hadrosaurid dinosaur from southern China". Acta Geologica Sinica (English Edition). 81 (4): 550–554. Bibcode:2007AcGlS..81..550M. doi:10.1111/j.1755-6724.2007.tb00978.x.
  3. Tsogtbaatar, K.; Weishampel, D.; Evans, D. C.; Watabe, M. (2014). "A New Hadrosauroid (Plesiohadros djadokhtaensis) from the Late Cretaceous Djadokhtan Fauna of Southern Mongolia". In Eberth, D. A.; Evans, D. C. (eds.). Hadrosaurs. Indiana University Press. pp. 108−135. ISBN   978-0-253-01385-9.
  4. Chen, Yang; Yin, Fuguang; Liu, Zixuan; Zhang, Ruigang; Li, Lianglin; Chen, Wei; Chen, Fei (2018). "渝东南正阳地区晚白垩世恐龙化石产出地层沉积环境特征" [Recent progress in the study of the sedimentary environment of Late Cretaceous dinosaur strata in Zhengyang area, southeastern Chongqing]. Geology in China (in Chinese). 45 (2): 414–415. doi:10.12029/gc20180217. ISSN   1000-3657.
  5. Lin, Yu; Wang, Jun; Luo, Liangdong; Li, Deliang; Xiong, Can; Xiao, Ming; Zhang, Saike; Fang, Ruize; Yang, Daifeng (2024-04-19). "渝东南正阳盆地晚白垩世构造—沉积演化" [Tectonic and sedimentary evolution of the Late Cretaceous Zhengyang Basin in southeastern Chongqing, SW China]. Geological Review (in Chinese). 70 (2): 2024020018–2024020018. doi:10.16509/j.georeview.2024.04.022. ISSN   0371-5736.