Nipponosaurus
Encyclopedia
Nipponosaurus is a lambeosaurine
hadrosaurid
from Asia
.
The holotype
(UHR 6590, University of Hokkaidō
Registration) was discovered in November 1934 during the construction of a hospital for the Kawakami colliery of the Mitsui Mining Company on Karafuto Prefecture
(now Sinegorsk, Sakhalin
, Russia
), and additional material belonging to the specimen was recovered in the summer of 1937. The type species
Nipponosaurus sachalinensis was in 1936 named and described by Professor Takumi Nagao of the Imperial University of Hokkaido. The generic name refers to Nippon
, the Japanese
name of Japan; it was the first dinosaur named based on a find made on Japanese territory — though South Sakhalin was annexed by the Soviet Union
in 1945. The specific name refers to Sakhalin. In 1938 Nagao dedicated a second article to the species.
The specimen was collected from Upper Yezo Group ("Upper Ammonite
s Bed) (late Santonian
— early Campanian
). UHR 6590 consists of a left maxilla
and dentary, parietal
, various isolated skull elements, thirteen cervical vertebrae
, six dorsal vertebrae, two sacral
vertebrae, a series of 35 caudal vertebrae, a left scapula
, distal portions of both humeri, most elements of the lower forelimbs, an ischium, left ilium
, and most of the hindlimbs. Though the quality of bone
preservation is generally poor, the skeleton
is estimated to be 60% complete. It nevertheless remains one of the most poorly known lambeosaurine dinosaur
s.
Nipponosaurus was recently redescribed by Suzuki et al. (2004), who diagnosed the taxon
as follows: "Robust coronoid process of the surangular, only slight development of the neural spine of the axis
, and strong deflection of the lateral margin of the first phalanx of digit IV."
Suzuki et al. (2004) have determined that the holotype represents a subadult individual, measuring roughly four meters (13 feet) in length. A cladistic analysis (Suzuki et al., 2004; pp. 160–161) places Nipponosaurus sachalinensis very close to the well-known North America
n Hypacrosaurus
altispinus within the Lambeosaurinae
. They denied the taxon was a nomen dubium
as has been concluded by several authors.
Lambeosaurinae
Lambeosaurinae is a group of crested hadrosaurid dinosaurs.-Classification:Lambeosaurines have been split into Parasaurolophini and Corythosaurini . Corythosaurini and Parasaurolophini as terms entered the formal literature in Evans and Reisz's 2007 redescription of Lambeosaurus magnicristatus...
hadrosaurid
Hadrosaurid
Hadrosaurids or duck-billed dinosaurs are members of the family Hadrosauridae, and include ornithopods such as Edmontosaurus and Parasaurolophus. They were common herbivores in the Upper Cretaceous Period of what are now Asia, Europe and North America. They are descendants of the Upper...
from Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
.
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...
(UHR 6590, University of Hokkaidō
Hokkaido University
Hokkaido University is one of the most prestigious universities in Japan. It can be seen in the several rankings such as shown below.-General Rankings:...
Registration) was discovered in November 1934 during the construction of a hospital for the Kawakami colliery of the Mitsui Mining Company on Karafuto Prefecture
Karafuto Prefecture
, commonly called South Sakhalin, was the Japanese administrative division corresponding to Japanese territory on Sakhalin from 1905 to 1945. Through the Treaty of Portsmouth, the portion of Sakhalin south of 50°N became a colony of Japan in 1905...
(now Sinegorsk, Sakhalin
Sakhalin
Sakhalin or Saghalien, is a large island in the North Pacific, lying between 45°50' and 54°24' N.It is part of Russia, and is Russia's largest island, and is administered as part of Sakhalin Oblast...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
), and additional material belonging to the specimen was recovered in the summer of 1937. 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...
Nipponosaurus sachalinensis was in 1936 named and described by Professor Takumi Nagao of the Imperial University of Hokkaido. The generic name refers to Nippon
Nippon
Nippon is a native name for Japan, more formal than Nihon.Nippon can also refer to:-Company names:All of the following companies are based in Japan.*Nikon *Nippon Telegraph and Telephone...
, the Japanese
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
name of Japan; it was the first dinosaur named based on a find made on Japanese territory — though South Sakhalin was annexed by the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
in 1945. The specific name refers to Sakhalin. In 1938 Nagao dedicated a second article to the species.
The specimen was collected from Upper Yezo Group ("Upper Ammonite
Ammonite
Ammonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct subclass within the Molluscan class Cephalopoda which are more closely related to living coleoids Ammonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct...
s Bed) (late Santonian
Santonian
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous epoch or Upper Cretaceous series. It spans the time between 85.8 ± 0.7 mya and 83.5 ± 0.7 mya...
— early Campanian
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...
). UHR 6590 consists of a left maxilla
Maxilla
The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...
and dentary, parietal
Parietal
Parietal may refer to:*Parietal placentation*Parietal lobe of the brain*Parietal bone of the skull*Parietal scales of a snake lie in the general region of the parietal bone*Parietal cell in the stomach*Parietal pleura...
, various isolated skull elements, thirteen cervical vertebrae
Cervical vertebrae
In vertebrates, cervical vertebrae are those vertebrae immediately inferior to the skull.Thoracic vertebrae in all mammalian species are defined as those vertebrae that also carry a pair of ribs, and lie caudal to the cervical vertebrae. Further caudally follow the lumbar vertebrae, which also...
, six dorsal vertebrae, two sacral
Sacral
Sacral may refer to:*sacred*sacrum...
vertebrae, a series of 35 caudal vertebrae, a left scapula
Scapula
In anatomy, the scapula , omo, or shoulder blade, is the bone that connects the humerus with the clavicle ....
, distal portions of both humeri, most elements of the lower forelimbs, an ischium, left 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 ,...
, and most of the hindlimbs. Though the quality of bone
Bone
Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
preservation is generally poor, the skeleton
Skeleton
The skeleton is the body part that forms the supporting structure of an organism. There are two different skeletal types: the exoskeleton, which is the stable outer shell of an organism, and the endoskeleton, which forms the support structure inside the body.In a figurative sense, skeleton can...
is estimated to be 60% complete. It nevertheless remains one of the most poorly known lambeosaurine dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
s.
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
as follows: "Robust coronoid process of the surangular, only slight development of the neural spine of the axis
Axis (anatomy)
In anatomy, the second cervical vertebra of the spine is named the axis or epistropheus.It forms the pivot upon which the first cervical vertebra , which carries the head, rotates....
, and strong deflection of the lateral margin of the first phalanx of digit IV."
Suzuki et al. (2004) have determined that the holotype represents a subadult individual, measuring roughly four meters (13 feet) in length. A cladistic analysis (Suzuki et al., 2004; pp. 160–161) places Nipponosaurus sachalinensis very close to the well-known North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
n Hypacrosaurus
Hypacrosaurus
Hypacrosaurus was a genus of duckbill dinosaur similar in appearance to Corythosaurus. Like Corythosaurus, it had a tall, hollow rounded crest, although not as large and straight...
altispinus within the Lambeosaurinae
Lambeosaurinae
Lambeosaurinae is a group of crested hadrosaurid dinosaurs.-Classification:Lambeosaurines have been split into Parasaurolophini and Corythosaurini . Corythosaurini and Parasaurolophini as terms entered the formal literature in Evans and Reisz's 2007 redescription of Lambeosaurus magnicristatus...
. They denied the taxon was a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
as has been concluded by several authors.