''Zizhongosaurus'' (meaning "Zizhong 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 ...

of basal

herbivorous A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

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 ...

which lived in the

Early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-J ...

(

Toarcian The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian ...

) Period of

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

. It was a large-bodied herbivore characterized by a long neck.

Discovery and naming

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 ...

''Zizhongosaurus chuanchengensis'' was named in 1983 by

Dong Zhiming Dong Zhiming (Chinese: 董枝明, Pinyin: ''Dǒng Zhimíng''; born January 1937) is a Chinese vertebrate paleontologist formerly employed at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing. He began working at the ...

Zhou Shiwu Zhou may refer to: Chinese history * King Zhou of Shang () (1105 BC–1046 BC), the last king of the Shang dynasty * Predynastic Zhou (), 11th-century BC precursor to the Zhou dynasty * Zhou dynasty () (1046 BC–256 BC), a dynasty of China ** West ...

and Zhang Yihong. The generic name is derived from

Zizhong County Zizhong County is a county of Sichuan Province Sichuan (; zh, c=, labels=no, ; zh, p=Sìchuān; alternatively romanized as Szechuan or Szechwan; formerly also referred to as "West China" or "Western China" by Protestant missions) is a ...

Sichuan Sichuan (; zh, c=, labels=no, ; zh, p=Sìchuān; alternatively romanized as Szechuan or Szechwan; formerly also referred to as "West China" or "Western China" by Protestant missions) is a province in Southwest China occupying most of the ...

Province. The specific name refers to the town of Chuancheng. The

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

s consist of three

syntype In biological nomenclature, a syntype is any one of two or more biological types that is listed in a description of a taxon where no holotype was designated. Precise definitions of this and related terms for types have been established as part of ...

s: V9067.1 is a partial dorsal

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

; V9067.2 is a

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

or upper arm; and V9067.3 is a pubis. All specimens likely were part of a single skeleton, collected from the

Ziliujing Formation The Ziliujing Formation is a geological formation in China, It is Early Jurassic in age. It is part of the stratigraphy of the Sichuan Basin. The dinosaur ''Gongxianosaurus'' and indeterminate theropod material are known from the Dongyuemiao Mem ...

. ''Zizhongosaurus'' was described as a small species.Dong, Z., Zhou, S., Zhang, Y. (1983). "Dinosaurs from the Jurassic of Sichuan". ''Palaeontologica Sinica'' 162 New Series C 23. Science Press Peking: pp. 1-136 In 1999 Li Kui mentioned a second species: ''Zizhongosaurus huangshibanensis''K. Li, Y. Zhang, K. Cai, 1999, ''The Characteristics of the Composition of the Trace Elements in Jurassic Dinosaur Bones and Red Beds in Sichuan Basin'', Geological Publishing House, Beijing but this has remained an undescribed ''

nomen nudum In taxonomy, a ''nomen nudum'' ('naked name'; plural ''nomina nuda'') is a designation which looks exactly like a scientific name of an organism, and may have originally been intended to be one, but it has not been published with an adequate descr ...

''.

Classification

''Zizhongosaurus'' was originally assigned to the Cetiosaurinae but later authors have placed it in either the

Vulcanodontidae The Early Jurassic sauropod dinosaurs ''Zizhongosaurus'', ''Barapasaurus'', ''Tazoudasaurus'', and ''Vulcanodon'' may form a natural group of basal sauropods called the Vulcanodontidae. Basal vulcanodonts include some of the earliest known examp ...

, as a relative of ''

Barapasaurus ''Barapasaurus'' ( ) is a genus of basal sauropod dinosaur from Early Jurassic rocks of India. The only species is ''B. tagorei''. ''Barapasaurus'' comes from the lower part of the Kota Formation, that dates back to the Sinemurian and Pliensbac ...

'', or the Shunosaurinae. It is today often considered a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

''.

References

Early Jurassic dinosaurs of Asia Vulcanodontidae Taxa named by Dong Zhiming Fossil taxa described in 1983 Paleontology in Sichuan Nomina dubia {{Sauropodomorph-stub