''Ruyangosaurus'' (

Ruyang County Ruyang County () is a county in the west of Henan province, China, under the jurisdiction of the prefecture-level city of Luoyang. Ruyang County has been the site of several major discoveries of fossilized dinosaur bones, including ''Huanghetit ...

lizard) is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

titanosauriform Macronaria is a clade of sauropod dinosaurs. Macronarians are named after the large diameter of the nasal opening of their skull, known as the external naris, which exceeded the size of the orbit, the skull opening where the eye is located (hence ...

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their bo ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

recovered from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

Haoling Formation The Haoling Formation is a Mesozoic geologic formation in the Ruyang Basin of Henan, Province, central China. Dinosaur remains are among the fossils that have been recovered from the formation. The Haoling Formation was originally treated as part ...

of China. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

is ''R. giganteus'', described in

2009 File:2009 Events Collage V2.png, From top left, clockwise: The vertical stabilizer of Air France Flight 447 is pulled out from the Atlantic Ocean; Barack Obama becomes the first African American to become President of the United States; 2009 Iran ...

Lü Junchang Lü Junchang (; 1965 – 9 October 2018) 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 ...

''et al''.

Description

Along with ''

Huanghetitan ''Huanghetitan'' (meaning "Yellow River titan"), is a genus of sauropod dinosaur from the early Cretaceous Period. It was a basal titanosauriform which lived in what is now Gansu, China. History The type species, ''Huanghetitan liujiaxiaens ...

'' and ''

Daxiatitan ''Daxiatitan'' (; meaning "Daxia giant" after a tributary of the Yellow River) 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 p ...

'', ''Ruyangosaurus'' is among the largest dinosaurs discovered in

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

Asia. In 2016

Gregory S. Paul Gregory Scott Paul (born December 24, 1954) is an American freelance researcher, author and illustrator who works in paleontology, and more recently has examined sociology and theology. He is best known for his work and research on theropod dino ...

gave a length of 30 meters (100 ft) and a weight of 50+ tonnes (55 short tons) - making it a 'mega-sauropod'. ''Ruyangosaurus'' was probably about 35 meters (115 ft) long, as evidenced by its 207 cm long femur and 127 cm long right tibia.

Classification

The describers of ''Ruyangosaurus'' assigned it to Andesauridae. However, Andesauridae is not monophyletic and, as such, is no longer used. Comprehensive phylogenetic analyses of Titanosauriformes conducted by Philip Mannion and colleagues in 2013 found ''Ruyangosaurus'' to be in a polytomy with ''

Andesaurus ''Andesaurus'' ( ; "Andes lizard") is a genus of basal titanosaurian sauropod dinosaur which existed during the middle of the Cretaceous Period in South America. Like most sauropods, belonging to one of the largest animals ever to walk the Eart ...

'' and other basal titanosaurs and near-titanosaur somphospondyls, supporting the original description's assertion of phylogenetic proximity of it and ''Andesaurus'', though not the precise taxonomic assignment, with further modifications of the dataset resolving similar conclusions. However, not all phylogenetic analyses have supported its position as a somphospondyl. A phylogenetic dataset following the description of additional material for ''Ruyangosaurus'' to be a non-titanosauriform macronarian, closely related to ''

Yunmenglong ''Yunmenglong'' (meaning "Yunmeng dragon", after the Yunmengshan area where it was found) is an extinct genus of somphospondylan sauropod known from the late Early Cretaceous of Henan Province, central China. Its remains were discovered in the ...

''. The phylogenetic analysis of Mannion ''et al.'' in 2019 incorporated these updated discoveries into their earlier analysis, along with additional new knowledge for other mid-Cretaceous Asian taxa considered close to Titanosauria. They found ''Ruyangosaurus'' to either be close to ''Andesaurus'' as a basal titanosaur when all characters were considered equally important, or in a large clade of early titanosaurs potentially given the name

Euhelopodidae Euhelopodidae is a family of sauropod dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact or ...

related to taxa like ''

Yongjinglong ''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''. Discovery ''Yongjinglong'' wa ...

'' and ''

Huanghetitan ruyangensis ''Huanghetitan'' (meaning "Yellow River titan"), is a genus of sauropod dinosaur from the early Cretaceous Period. It was a basal titanosauriform which lived in what is now Gansu, China. History The type species, ''Huanghetitan liujiaxiaens ...

''. Two trees of the results are shown below, equal weighting displaying the results of basal titanosauria, and relationships within Euhelopodidae of extended-implied weighting with a mild down-weighting of highly variable characters (k=9).

Habitat

''Ruyangosaurus'' shared its habitat with ''

Xianshanosaurus ''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 ...

'', ''"

" ruyangensis'', ''

'', ''

Luoyanggia ''Luoyanggia'' (meaning "from Luoyang") is a genus of oviraptorid dinosaur known from the Early Cretaceous Haoling Formation of the Ruyang Basin in Henan Province, central China. The type species is ''L. liudianensis''.Lü., J., Xu, L., Jiang, ...

'', and ''

Zhongyuansaurus ''Zhongyuansaurus'' (meaning “Zhongyuan lizard”) is a monospecific genus of ankylosaurid dinosaur from Henan that lived during the Early Cretaceous (Aptian-Albian, ~125.0-100.5 Ma) in what is now the Haoling Formation. ''Zhongyuansaurus '' i ...

''. The type horizon of ''Ruyangosaurus'' was originally described as being of "early

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

" age, but recent work has assigned it an Aptian-Albian Age based on fieldwork and analysis of invertebrate and microfossil assemblages.Xu, L., Pan, Z.C., Wang, Z.H., Zhang, X.L., Jia, S.H., Lü, J.C., Jiang, B.L., 2012. Discovery and significance of the Cretaceous system in Ruyang Basin, Henan Province. Geological Review 58, 601-613.

References

{{Portal bar, Dinosaurs, Paleontology, Cretaceous, China Early Cretaceous dinosaurs of Asia Titanosaurs Fossil taxa described in 2009 Taxa named by Lü Junchang Paleontology in Henan

Description

Classification

Habitat

See also

References