''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 extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
saurolophine
Saurolophinae is a subfamily (biology), 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. How ...
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 inclu ...
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 ...
of
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
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 ...
. Its remains were found in a
bonebed
A bone bed is any geological stratum or deposit that contains bones of whatever kind. Inevitably, such deposits are sedimentary in nature. Not a formal term, it tends to be used more to describe especially dense collections such as Lagerstätt ...
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 interval from ...
-age
Yuliangze Formation
The Yuliangze Formation, or Yuliangzi Formation, is a geological formation in Heilongjiang, China whose strata date back to the early-middle Maastrichtian. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampe ...
, 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 (''Cor ...
hadrosaurid (hollow-crested duckbill) ''
Sahaliyania''. ''Wulagasaurus'' was named by
Pascal Godefroit Pascal Godefroit is a Belgian paleontologist. He discovered dinosaurs like '' Olorotitan'' in 2003. Godefroit is the director of earth and life sciences
This list of life sciences comprises the branches of science that involve the scientific st ...
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 List of longest rivers, tenth longest river, forming the border between the Russian Far East and Northeast China, Northeastern China (Inne ...
region named since 2000. The
type and only species to date is ''W. dongi'', named in honor of Chinese paleontologist
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 ...
.
In 2010
Gregory S. Paul
Gregory Scott Paul (born December 24, 1954) is an American freelance researcher, author and illustrator who works in paleontology, and more recently has examined sociology and theology. He is best known for his work and research on theropod dino ...
estimated its size at 9 meters (30 ft) and 3 tonnes (3.3 short tons).
''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 tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
(toothbearing bone of the lower jaw). Godefroit and colleagues assigned additional remains from the bonebed to their new genus, including three
braincase
In human anatomy, the neurocranium, also known as the braincase, brainpan, or brain-pan is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the calvaria or skul ...
s, 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 is s ...
, 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 t ...
e (the toothbearing bone of the upper jaw), another dentary, two
shoulder blades, two
sternal
The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Sh ...
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
. It can be
distinguished
The ruling made by the judge or panel of judges must be based on the evidence at hand and the standard binding precedents covering the subject-matter (they must be ''followed'').
Definition
In law, to distinguish a case means a court decides th ...
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, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
that suggests ''Wulagasaurus'' was the most
basal 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 mouthpart ...
.
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 suggest ...
'' (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 Republic ...
'', ''
American Museum of Natural History
The American Museum of Natural History (abbreviated as AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. In Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 26 inter ...
'', and ''
Geological Museum of Heilongjiang Provinces'', 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
''Brachylophosaurus'' ( or ; meaning "short-crested lizard", Greek ''brachys'' = short + ''lophos'' = crest + ''sauros'' = lizard, referring to its small crest) was a mid-sized member of the hadrosaurid family of dinosaurs. It is known from sev ...
'' 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 curre ...
'', possibly forming a clade-structure within the already existing clade
Brachylophosaurini
Brachylophosaurini is a tribe of saurolophine hadrosaurs with known material being from N. America and potentially Asia. It contains at least four taxa; '' Acristavus'' (from Montana and Utah), '' Brachylophosaurus'' (from Montana and Alberta), ...
.
This hypothesis has been demonstrated by another phylogenetic analysis recently coming out.
See also
*
Timeline of hadrosaur research
A timeline is a display of a list of events in chronological order. It is typically a graphic design showing a long bar labelled with dates paralleling it, and usually contemporaneous events.
Timelines can use any suitable scale represent ...
References
{{Taxonbar, from=Q2362767
Late Cretaceous dinosaurs of Asia
Saurolophines
Fossil taxa described in 2008
Ornithischian genera