Shenzhousaurus
Encyclopedia
Shenzhousaurus is a genus
of basal
ornithomimosaur from the Lower Cretaceous
of China
.
The holotype
(NGMC 97-4-002, National Geological Museum of China) was collected from near the bottom (fluvial
beds) of the Yixian Formation
(Aptian
) at the Sihetun fossil site, Beipiao, western Liaoning
Province. This specimen consists of a partial skeleton preserved on a sandstone
slab in a "death pose
," its head above the torso
. The distal parts of the hindlimbs, distal portion of the tail, and the forelimb
s (except for part of the right hand) and the pectoral girdle are missing. The head is crushed, exposing the left side obliquely.
Shenzhousaurus was first described by Qiang Ji, Mark Norell, Peter J. Makovicky, Keqin Gao, Shu-An Ji and Chongxi Yuan in 2003
and the type species
is Shenzhousaurus orientalis. The genus is currently monotypic
and appears to be more derived than Pelecanimimus
polyodon, yet less derived than Harpymimus
oklandikovi. It may be distinguished from the latter by its "straight ischial shaft and acuminateposterior end of the ilium
" (Makovicky et al., 2004), and from all other ornithomimosaurs excepting Harpymimus by the relative length of metacarpal I (only half that of metacarpal II) and in that its reduced dentition
is restricted to the symphyseal portion of the dentary. The holotype skull measure 185 mm. A number of pebbles
found in the thoracic cavity have been interpreted as gastrolith
s.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
ornithomimosaur from the Lower Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
of China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
.
The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
(NGMC 97-4-002, National Geological Museum of China) was collected from near the bottom (fluvial
Fluvial
Fluvial is used in geography and Earth science to refer to the processes associated with rivers and streams and the deposits and landforms created by them...
beds) of the Yixian Formation
Yixian Formation
The Yixian Formation is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans 11 million years during the early Cretaceous period...
(Aptian
Aptian
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma , approximately...
) at the Sihetun fossil site, Beipiao, western Liaoning
Liaoning
' is a province of the People's Republic of China, located in the northeast of the country. Its one-character abbreviation is "辽" , a name taken from the Liao River that flows through the province. "Níng" means "peace"...
Province. This specimen consists of a partial skeleton preserved on a sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
slab in a "death pose
Death pose
Dinosaurs and bird fossils are frequently found in a characteristic posture consisting of head thrown back, tail extended, and mouth wide open. The cause of this posture—sometimes called a "death pose"—has been a matter of scientific debate...
," its head above the torso
Torso
Trunk or torso is an anatomical term for the central part of the many animal bodies from which extend the neck and limbs. The trunk includes the thorax and abdomen.-Major organs:...
. The distal parts of the hindlimbs, distal portion of the tail, and the forelimb
Forelimb
A forelimb is an anterior limb on an animal's body. When referring to quadrupeds , the term foreleg is often instead used....
s (except for part of the right hand) and the pectoral girdle are missing. The head is crushed, exposing the left side obliquely.
Shenzhousaurus was first described by Qiang Ji, Mark Norell, Peter J. Makovicky, Keqin Gao, Shu-An Ji and Chongxi Yuan in 2003
2003 in paleontology
-New taxa:-Newly named dinosaurs:Data courtesy of George Olshevsky's dinosaur genera list and Dr. Jeremy Montague's dinosaur genus database.-New taxa:-New taxa:-Non-mammalian:-newly named:-Conifers:-Angiosperms:...
and the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
is Shenzhousaurus orientalis. The genus is currently monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
and appears to be more derived than Pelecanimimus
Pelecanimimus
Pelecanimimus is a genus of basal ornithomimosaurian theropod dinosaur from the Early Cretaceous of Spain...
polyodon, yet less derived than Harpymimus
Harpymimus
Harpymimus is a basal ornithomimosaurian theropod dinosaur from the Early Cretaceous Period of what is now Mongolia. Unlike later, more derived ornithomimosaurs, Harpymimus still possessed teeth, although they appear to have been restricted to the dentary of the lower jaw.-Discovery and naming:In...
oklandikovi. It may be distinguished from the latter by its "straight ischial shaft and acuminateposterior end of the ilium
Ilium (bone)
The ilium is the uppermost and largest bone of the pelvis, and appears in most vertebrates including mammals and birds, but not bony fish. All reptiles have an ilium except snakes, although some snake species have a tiny bone which is considered to be an ilium.The name comes from the Latin ,...
" (Makovicky et al., 2004), and from all other ornithomimosaurs excepting Harpymimus by the relative length of metacarpal I (only half that of metacarpal II) and in that its reduced dentition
Dentition
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, the characteristic arrangement, kind, and number of teeth in a given species at a given age...
is restricted to the symphyseal portion of the dentary. The holotype skull measure 185 mm. A number of pebbles
Pebble
A pebble is a clast of rock with a particle size of 4 to 64 millimetres based on the Krumbein phi scale of sedimentology. Pebbles are generally considered to be larger than granules and smaller than cobbles . A rock made predominantly of pebbles is termed a conglomerate...
found in the thoracic cavity have been interpreted as gastrolith
Gastrolith
A gastrolith, also called a stomach stone or gizzard stones, is a rock held inside a gastrointestinal tract. Gastroliths are retained in the muscular gizzard and used to grind food in animals lacking suitable grinding teeth. The grain size depends upon the size of the animal and the gastrolith's...
s.
External links
- dinosaur.net.cn http://www.dinosaur.net.cn/museum/Shenzhousaurus.htm (includes images of specimen and a life restoration)