Liubangosaurus

Sauropod remains were first discovered at the Liubang Quarry in 2001, near the village of the same name (Liubang) which is near the city of Nanning in the Guangxi Province of southern China. This locality corresponds to the Napai Formation, which is Early Cretaceous in age. Subsequent excavations determined that remains from a minimum of three individual specimens were present in the quarry. The largest of these would eventually be described as the new genus Fusuisaurus. The two smaller specimens were mostly disarticulated, which made it difficult for researchers to distinguish which bones belonged to which individuals. The remains were excavated with the help of the Natural History Museum of Guangxi, which is where the specimens were eventually stored. However, five caudal vertebrae among these remains were articulated, which was deemed sufficient to name and describe the new genus and species Liubangosaurus hei. It was fully described and named in 2010 by Mo Jinyou, Xu Xing, and Eric Buffetaut.

The holotype of Liubangosaurus was given the specimen number NHMG 8152. It consists of five articulated dorsal vertebrae, believed to represent the fifth through ninth dorsal vertebrae. The largest of these vertebrae (the fifth dorsal) has a total height of {{convert|710|mm|in|abbr=on}}. The fragmentary nature of the specimen makes the full size of Liubangosaurus difficult to estimate. Rubén Molina-Pérez and Asier Larramendi estimated its full size as being {{convert|26|m|ft|abbr=on}} long, {{convert|5.4|m|ft|abbr=on}} tall at the shoulder, and 26 tons{{Cite book |last1=Molina-Pérez |first1=Rubén |last2=Larramendi |first2=Asier |date=29 September 2020 |title=Dinosaur Facts and Figures: The Sauropods and Other Sauropodomorphs |translator-last1=Donaghey |translator-first1=Joan |others=Illustrated by Andrey Atuchin and Sante Mazzei |publisher=Princeton University Press |isbn=978-0-691-19069-3 |url=https://books.google.com/books?id=d-HFDwAAQBAJ |doi=10.2307/j.ctvt7x71z}}

Despite consisting of only five vertebrae, the holotype of Liubangosaurus preserves several autapomorphies. These include features of the {{dinogloss|parapophyses}}, {{dinogloss|diapophyses}}, neural spines, and vertebral laminae. In particular, the vertebrae have a very distinctive "Y-shape" when viewed along their transverse plane.

In their description of Liubangosaurus, Mo and colleagues conducted a phylogenetic analysis of neosauropods in order to determine the affinities of the new species. The trees they recovered were not very resolved and recovered Liubangosaurus in a polytomy with other groups of neosauropods. They suggested that it may be a close relative of the Late Jurassic genus Haplocanthosaurus, however they also caution that this assignment is very tentative due to the fragmentary nature of the holotype. Philip Mannion and colleagues published a comprehensive analysis of titanosauriform relationships in 2013. They used two different analytical methods to test these relationships, and both methods recovered different relationships for Liubangosaurus.{{Cite journal|last1=Mannion|first1=Philip D.|last2=Upchurch|first2=Paul|last3=Barnes|first3=Rosie N.|last4=Mateus|first4=Octávio|date=2013|title=Osteology of the Late Jurassic Portuguese sauropod dinosaur Lusotitan atalaiensis (Macronaria) and the evolutionary history of basal titanosauriforms|journal=Zoological Journal of the Linnean Society|language=en|volume=168|issue=1|pages=98–206|doi=10.1111/zoj.12029|issn=1096-3642|doi-access=free}} The fragmentary nature of Liubangosaurus has served to complicate determinations of its phylogenetic affinities. Several recent analyses omit it entirely from their consensus trees.{{cite journal |doi=10.1098/rsos.191057 |title=New information on the Cretaceous sauropod dinosaurs of Zhejiang Province, China: Impact on Laurasian titanosauriform phylogeny and biogeography |date=2019 |last1=Mannion |first1=Philip D. |last2=Upchurch |first2=Paul |last3=Jin |first3=Xingsheng |last4=Zheng |first4=Wenjie |journal=Royal Society Open Science |volume=6 |issue=8 |pmid=31598266 |pmc=6731702 |bibcode=2019RSOS....691057M }}{{cite journal |doi=10.1093/zoolinnean/zlad124 |title=New sauropod dinosaur from the Lower Cretaceous of Morella (Spain) provides new insights on the evolutionary history of Iberian somphospondylan titanosauriforms |date=2024 |last1=Mocho |first1=Pedro |last2=Escaso |first2=Fernando |last3=Gasulla |first3=José M. |last4=Galobart |first4=Àngel |last5=Poza |first5=Begoña |last6=Santos-Cubedo |first6=Andrés |last7=Sanz |first7=José L. |last8=Ortega |first8=Francisco |journal=Zoological Journal of the Linnean Society |volume=201 |pages=214–268 }} Condensed versions of the cladograms recovered by Mo and colleagues and also by Mannion and colleagues are shown below.

{{columns-start|num=2}}

;Mo, Xu, & Buffetaut, 2010

{{clade

|label1=Neosauropoda

|1={{clade

|1=Jobaria 70px

|2={{clade

|1=Haplocanthosaurus

|2=Liubangosaurus

}}

|3=Diplodocoidea 100px

|4=Macronaria 110px

}}

}}

;Mannion et al. 2013, strict consensus

{{clade| style=font-size:80%; line-height:70%

|label1=Titanosauria

|1={{clade

|1=Diamantinasaurus

|2=Xianshanosaurus

|label3=Lithostrotia

|3={{clade

|1=Malawisaurus

|label2=Saltasauridae

|2={{clade

|1={{clade sequential

|1=Saltasaurus 80px

|2=Alamosaurus 90px

|3=Jiangshanosaurus

}}

|2={{clade sequential

|1=Liubangosaurus

|2=Dongyangosaurus

|3=Opisthocoelicaudia 80px

}}

}}

}}

}}

}}

{{column}}

;Mannion et al. 2013, strict reduced consensus

{{clade| style=font-size:80%; line-height:70%

|label1=Somphospondyli

|1={{clade

|1=Dongbeititan

|2={{clade

|label1=Euhelopodidae

|1={{clade

|2=Liubangosaurus

|1={{clade

|1={{clade sequential

|1=Gobititan

|2=Phuwiangosaurus

|3=Tangvayosaurus

}}

|2={{clade sequential

|1=Qiaowanlong

|2=Erketu

|3=Euhelopus 70px

}}

}}

}}

|2={{clade

|1=Brontomerus

|2={{clade

|1={{clade

|1={{clade

|1=Sonorasaurus 70px

|2=Tastavinsaurus

}}

|2={{clade

|1=Diamantinasaurus

|2=Haestasaurus

}}

}}

|2={{clade

|1=Sauroposeidon 90px

|2={{clade

|1={{clade

|1=Ruyangosaurus

|2=Wintonotitan

}}

|2={{clade sequential

|1=Huanghetitan liujiaxiaensis

|2="Huanghetitan" ruyangensis

|3=Titanosauria 90px

}}

}}

}}

}}

}}

}}

}}

}}

{{columns-end}}

The Xinlong Formation is an Aptian-aged geological formation that consists mainly of various types of siltstones, fine sandstones, some mudstones and sandy conglomerates. The depositional environment consisted of various types of wetlands, which is reflected in the fossils that have been discovered in the area. Bivalve, charophyte, ostracod, and gastropod fossils are common alongside remains from hybodontiformes, bowfins, gars, turtles, and some crocodyliformes. Dinosaurs known from the area include the sauropods Asiatosaurus and Fusuisaurus, remains from spinosaurids, and some indeterminate ornithopods.{{cite journal |doi=10.1017/S0016756815000394 |title=Early Cretaceous vertebrates from the Xinlong Formation of Guangxi (Southern China): A review |date=2016 |last1=Mo |first1=Jinyou |last2=Buffetaut |first2=Eric |last3=Tong |first3=Haiyan |last4=Amiot |first4=Romain |last5=Cavin |first5=Lionel |last6=Cuny |first6=Gilles |last7=Suteethorn |first7=Varavudh |last8=Suteethorn |first8=Suravech |last9=Jiang |first9=Shan |journal=Geological Magazine |volume=153 |issue=1 |pages=143–159 |bibcode=2016GeoM..153..143M }}

• 2010 in archosaur paleontology
• List of Asian dinosaurs
• List of sauropod species
• List of sauropodomorph type specimens

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{{Sauropodomorpha|M.}}

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Category:Macronaria

Category:Dinosaur genera

Category:Aptian dinosaurs

Category:Fossil taxa described in 2010

Category:Taxa named by Xu Xing

Category:Taxa named by Éric Buffetaut

Category:Dinosaurs of China