''Wulagasaurus'' (meaning "Wulaga lizard", in reference to the discovery locality) is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

saurolophine Saurolophinae is a subfamily of hadrosaurid dinosaurs. It has since the mid-20th century generally been called the Hadrosaurinae, a group of largely non-crested hadrosaurs related to the crested sub-family Lambeosaurinae. However, the name Had ...

hadrosaurid Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which incl ...

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'', ...

Heilongjiang Heilongjiang () formerly romanized as Heilungkiang, is a province in northeast China. The standard one-character abbreviation for the province is (). It was formerly romanized as "Heilungkiang". It is the northernmost and easternmost province ...

, China. Its remains were found in a bonebed in the middle

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interv ...

-age Yuliangze Formation, dated to 69 million years ago.Godefroit, P., Lauters, P., Van Itterbeeck, J., Bolotsky, Y. and Bolotsky, I.Y. (2011). "Recent advances on study of hadrosaurid dinosaurs in Heilongjiang (Amur) River area between China and Russia." ''Global Geology'', 2011(3). This bonebed is otherwise dominated by fossils of the

lambeosaurine Lambeosaurinae is a group of crested hadrosaurid dinosaurs. Classification Lambeosaurines have been traditionally split into the tribes or clades Parasaurolophini (''Parasaurolophus'', '' Charonosaurus'', others (?).) and Lambeosaurini ('' ...

hadrosaurid (hollow-crested duckbill) ''

Sahaliyania ''Sahaliyania'' (from "black" in Manchu, a reference to the Amur/ Heilongjiang River) is a genus of lambeosaurine hadrosaurid dinosaur (crested duckbilled dinosaur) from the Late Cretaceous of Heilongjiang, China. Discovery Its remains were ...

''. ''Wulagasaurus'' was named by Pascal Godefroit and colleagues in 2008. Only partial remains are known at this time. It is one of several hadrosaurids from the

Amur River The Amur (russian: река́ Аму́р, ), or Heilong Jiang (, "Black Dragon River", ), is the world's tenth longest river, forming the border between the Russian Far East and Northeastern China ( Inner Manchuria). The Amur proper is long ...

region named since 2000. The

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

and only species to date is ''W. dongi'', named in honor of Chinese paleontologist Dong Zhiming. In 2010 Gregory S. Paul estimated its size at 9 meters (30 ft) and 3 tonnes (3.3 short tons). Wulagasaurus revision

''Wulagasaurus'' is based on GMH W184, a partial

dentary In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

(toothbearing bone of the lower jaw). Godefroit and colleagues assigned additional remains from the bonebed to their new genus, including three braincases, a

cheekbone In the human skull, the zygomatic bone (from grc, ζῠγόν, zugón, yoke), also called cheekbone or malar bone, is a paired irregular bone which articulates with the maxilla, the temporal bone, the sphenoid bone and the frontal bone. It ...

, two

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The ...

e (the toothbearing bone of the upper jaw), another dentary, two

shoulder blades The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on either ...

, two sternal elements, two

upper arm In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...

bones, and an

ischium The ischium () form ...

. It can be distinguished from other hadrosaurids by its slender dentary and the unique form of its upper arm, which had distinctive articulations and placements for muscle attachments. Godefroit and colleagues performed a

phylogenetic analysis In biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that pro ...

that suggests ''Wulagasaurus'' was the most

basal Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''. Science * Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure * Basal (medicine), a minimal level that is nec ...

saurolophine known (which would result in a long ghost lineage), and interpreted this as evidence that saurolophines and hadrosaurids in general originated in Asia, which has been supported by other finds since. As a hadrosaurid, ''Wulagasaurus'' would have been an

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 mouthp ...

. In recent studies conducted by researchers from the ''

Institute of Vertebrate Paleontology and Paleoanthropology The Institute of Vertebrate Paleontology and Paleoanthropology (IVPP; ) of China is a research institution and collections repository for fossils, including many dinosaur and pterosaur specimens (many from the Yixian Formation). As its name sugges ...

'' (IVPP), along with others from ''

Chinese Academy of Science The Chinese Academy of Sciences (CAS); ), known by Academia Sinica in English until the 1980s, is the national academy of the People's Republic of China for natural sciences. It has historical origins in the Academia Sinica during the Republ ...

'', '' American Museum of Natural History'', and ''

Geological Museum of Heilongjiang Provinces Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ea ...

'', re-evaluated and re-described ''Wulagasaurus dongi''. Based on both original and recent specimens, they concluded that ''Wulagasaurus'' shared many morphological similarities with North American taxon's '' Brachylophosaurus'' and ''

Maiasaura ''Maiasaura'' (from the Greek ''μαῖα'', meaning "good mother" and ''σαύρα'', the feminine form of ''saurus'', meaning "reptile") is a large herbivorous saurolophine hadrosaurid ("duck-billed") dinosaur genus that lived in the area curr ...

'', possibly forming a clade-structure within the already existing clade Brachylophosaurini. This hypothesis has been demonstrated by another phylogenetic analysis recently coming out.

References

{{Taxonbar, from=Q2362767 Late Cretaceous dinosaurs of Asia Saurolophines Fossil taxa described in 2008 Ornithischian genera

See also

References