Dyoplosaurus
Encyclopedia
Dyoplosaurus is the name given to a genus
of ankylosaurid dinosaur
. It lived during the Late Cretaceous
(Dinosaur Park Formation
, about 76.5 Ma ago) near what is now the Red Deer River
in Alberta
, Canada
and was named by William Parks in 1924, based on holotype
ROM 784, a partial skeleton including parts of the skull and lower jaws.
The type specimen of Dyoplosaurus was fifteen feet (four to five meters) long and about 5.8 feet (1.7 m) wide, with a skull measuring 14 inches (35 centimeters) across. Like most other ankylosaurids, it had an armored body and bony club on the end of its tail. The club was composed of several armor plates fused together.
Walter Coombs stated in 1971 that Dyoplosaurus is actually an incorrectly named Euoplocephalus
. The two were since generally assumed to be the same species and thus, former Dyoplosaurus specimens have been identified as Euoplocephalus tutus. However, a recent redescription of the genus published in 2009 in the Journal of Vertebrate Paleontology
claims that the genus is a valid taxon, suggesting that the proposed synonymy was due to the fragmentary nature of the holotype and other specimens of E. tutus. A new cladistic analysis performed by Thompson et al., 2011 confirmed this separation.
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 ankylosaurid 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...
. It lived during the Late 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...
(Dinosaur Park Formation
Dinosaur Park Formation
The Dinosaur Park Formation is the uppermost member of the Judith River Group, a major geologic unit in southern Alberta. It was laid down over a period of time between about 76.5 and 75 million years ago. The formation is made up of deposits of a high-sinuosity fluvial system, and is capped...
, about 76.5 Ma ago) near what is now the Red Deer River
Red Deer River
The Red Deer River is a river in Alberta, Canada. It is a major tributary of the South Saskatchewan River.Red Deer River has a total length of and a drainage area of...
in Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
and was named by William Parks in 1924, based on 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...
ROM 784, a partial skeleton including parts of the skull and lower jaws.
The type specimen of Dyoplosaurus was fifteen feet (four to five meters) long and about 5.8 feet (1.7 m) wide, with a skull measuring 14 inches (35 centimeters) across. Like most other ankylosaurids, it had an armored body and bony club on the end of its tail. The club was composed of several armor plates fused together.
Walter Coombs stated in 1971 that Dyoplosaurus is actually an incorrectly named Euoplocephalus
Euoplocephalus
Euoplocephalus was one of the largest genera of ankylosaurian dinosaurs, at about the size of a small elephant. It is also the ankylosaurian with the best fossil record, so its extensive spiked armor, low-slung body and great club-like tail are well documented.-Description:Among the...
. The two were since generally assumed to be the same species and thus, former Dyoplosaurus specimens have been identified as Euoplocephalus tutus. However, a recent redescription of the genus published in 2009 in the Journal of Vertebrate Paleontology
Journal of Vertebrate Paleontology
The Journal of Vertebrate Paleontology was founded in 1980 at the University of Oklahoma by Dr. Jiri Zidek. It is a scientific journal that publishes original contributions on all aspects of the vertebrate paleontology, including vertebrate origins, evolution, functional morphology, taxonomy,...
claims that the genus is a valid taxon, suggesting that the proposed synonymy was due to the fragmentary nature of the holotype and other specimens of E. tutus. A new cladistic analysis performed by Thompson et al., 2011 confirmed this separation.