''Dongyangosaurus'' 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
titanosaurian
Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thr ...
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 ...
from the
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 ...
.
The only species is ''Dongyangosaurus sinensis'', from which only a single fragmentary skeleton is known, coming from the
Zhejiang
Zhejiang ( or , ; , also romanized as Chekiang) is an eastern, coastal province of the People's Republic of China. Its capital and largest city is Hangzhou, and other notable cities include Ningbo and Wenzhou. Zhejiang is bordered by Jiang ...
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 where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuor' ...
al herbivore
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 ...
.[
]
Description
The only skeleton (holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...
DYM 04888) is stored in the Dongyang Museum (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 Region.
As ...
, Zhejiang). It consists of ten dorsal vertebrae, the sacrum, two caudal vertebrae
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 i ...
as well as the complete pelvis
The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton).
The ...
. 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
Skeletal pneumaticity is the presence of air spaces within bones. It is generally produced during development by excavation of bone by pneumatic diverticula (air sacs) from an air-filled space, such as the lungs or nasal cavity. Pneumatization is h ...
and low bifurcated neural spine
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 ...
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 (Latin foramen obturatum) is the large opening created by the ischium and pubis (bone), pubis bones of the pelvis through which nerves and blood vessels pass.
Structure
It is bounded by a thin, uneven margin, to which a str ...
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
Saltasauridae (named after the Salta region of Argentina where they were first found) is a family of armored herbivorous sauropods from the Upper Cretaceous. They are known from fossils found in South America, Asia, North America, and Europe. Th ...
closely related to the Mongolia
Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...
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'' ...
.
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
''Jiangshanosaurus'' is a genus of herbivorous titanosauriform sauropod dinosaur that lived in China approximately 92-88 million years ago, during the Turonian- Coniacian stage of the Late Cretaceous.
Discovery and naming
In 1977 and 1978 a ...
'' from the Jinhua Formation, the theropod
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...
'' Chilantaisaurus zhejiangensis'' (now known to have been an indeterminate theropod unrelated to ''Chilantaisaurus''), and the nodosaurid '' Zhejiangosaurus'' from the Chaochuan Formation. ''Dongyangosaurus'' comes from the Jinhua Formation. The age of this unit is considered Turonian
The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded b ...
-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 t ...
.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 Region.
As ...
, from which the generic name is derived. The specific name, ''sinensis'', is Greek
Greek may refer to:
Greece
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 ...
for "from China".[
]
References