''Dongyangosaurus'' is a
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
titanosaurian
Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of Sauropoda, sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with tax ...
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 b ...
dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...
from the
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent 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 ''cre ...
.
The only species is ''Dongyangosaurus sinensis'', from which only a single fragmentary skeleton is known, coming from the
Zhejiang
)
, translit_lang1_type2 =
, translit_lang1_info2 = ( Hangzhounese) ( Ningbonese) (Wenzhounese)
, image_skyline = 玉甑峰全貌 - panoramio.jpg
, image_caption = View of the Yandang Mountains
, image_map = Zhejiang i ...
province of eastern China. It was described and named by
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 ...
and colleagues.
[ Like other sauropods, ''Dongyangosaurus'' would have been a large ]quadruped
Quadrupedalism is a form of locomotion in which animals have four legs that are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four legs is said to be a quadruped (fr ...
al herbivore
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...
.[
]
Description
The only skeleton (holotype
A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...
DYM 04888) is stored in the Dongyang Museum (Dongyang
Dongyang () is a county-level city under the jurisdiction of Jinhua in Central Zhejiang Province, China. It covers an area of and administers eleven towns, one township, and six subdistricts. It is part of the Yangtze River Delta Economic Regi ...
, Zhejiang). It consists of ten dorsal vertebrae, the sacrum, two caudal vertebrae
Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...
as well as the complete pelvis
The pelvis (: pelves or pelvises) is the lower part of an Anatomy, anatomical Trunk (anatomy), trunk, between the human abdomen, abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also c ...
. The skeleton was found articulated.[
''Dongyangosaurus'' was a midsized sauropod, measuring approximately 50 ft (15 m) in length and 15 ft (5 m) in height. The dorsal vertebrae were characterized by eye shaped pleurocoels and low bifurcated ]neural spine
Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...
s. The sacrum consisted of six fused sacral vertebrae, a feature unique to somphospondylans.[ The caudal vertebrae were amphicoelous (concave anteriorly and posteriorly). The pubis was shorter than the . The ]obturator foramen
The obturator foramen is the large, Bilateral symmetry, bilaterally paired opening of the bony pelvis. It is formed by the pubis and ischium. It is mostly closed by the obturator membrane except for a small opening, the obturator canal, through wh ...
was narrow and extended.[
]
Systematics
When this genus was first described, it was thought to be a 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 ...
of uncertain placement. In 2013, however, it was found to be a saltasaurid closely related to the Mongolia
Mongolia is a landlocked country in East Asia, bordered by Russia to the north and China to the south and southeast. It covers an area of , with a population of 3.5 million, making it the world's List of countries and dependencies by po ...
n sauropod ''Opisthocoelicaudia
''Opisthocoelicaudia'' is a genus of sauropod dinosaur of the Late Cretaceous Period discovered in the Gobi Desert of Mongolia. The type species is ''Opisthocoelicaudia skarzynskii''. A well-preserved skeleton lacking only the head and neck wa ...
''.[ In 2019, this was again changed to a position outside of the ]Lithostrotia
Lithostrotia is a clade of derived titanosaur sauropods that lived during the Early Cretaceous and Late Cretaceous. The group was defined by Upchurch ''et al.'' in 2004 as the most recent common ancestor of ''Malawisaurus'' and ''Saltasaurus'' an ...
.
Discovery
The Upper Cretaceous of Zhejiang is known for its fossil dinosaur eggs. Skeletal remains are rarely found; the only described dinosaurs are the sauropod '' Jiangshanosaurus'' from the Jinhua Formation, the theropod
Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...
'' Chilantaisaurus zhejiangensis'' (now known to have been an indeterminate theropod unrelated to ''Chilantaisaurus''), and the nodosaurid ''Zhejiangosaurus
''Zhejiangosaurus'' (meaning "Zhejiang lizard") is an extinct genus of ankylosaurian dinosaur from the Upper Cretaceous (Cenomanian stage) of Zhejiang, eastern China. It was first named by a group of Chinese authors Lü Junchang, Jin Xingsheng, S ...
'' from the Chaochuan Formation. ''Dongyangosaurus'' comes from the Jinhua Formation. The age of this unit is considered Turonian
The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...
-Coniacian
The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded by ...
.Dongyang
Dongyang () is a county-level city under the jurisdiction of Jinhua in Central Zhejiang Province, China. It covers an area of and administers eleven towns, one township, and six subdistricts. It is part of the Yangtze River Delta Economic Regi ...
, from which the generic name is derived. The specific name, ''sinensis'', is Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
for "from China".[
]
References