Eobrontosaurus
Encyclopedia
Eobrontosaurus is the name given to a genus
of dinosaur
from the Late Jurassic
of North America
. It was a sauropod probably closely related to Apatosaurus
. It is known from a single site from the lower Morrison Formation
, dating to about 154 million years ago. It grew up to 21 metres (68.9 ft) long.
The type species
, E. yahnahpin, was described by James Filla and Patrick Redman in 1994 as a species of Apatosaurus
(A. yahnahpin). The specific name is derived from Lakota
mah-koo yah-nah-pin, "breast necklace", a reference to the pairs of sternal ribs that resemble the hair pipe
s traditionally worn by the tribe. The holotype
is TATE-001, a relatively complete postcrania
l skeleton found in Wyoming
, in the lower Morrison Formation
. More fragmentary remains have also been referred to the species.
A re-evaluation by Robert T. Bakker
in 1998 found it to be more primitive, and so Bakker coined the new generic name Eobrontosaurus, derived from Greek eos, "dawn", and Brontosaurus, the original generic name of Apatosaurus excelsus. It has been argued that Eobrontosaurus yahnahpin actually belongs within Camarasaurus
, although this has been questioned. According to Bakker Eobrontosaurus was a member of the Diplodocidae, more especially the Apatosaurinae.
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 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...
from the Late Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
of 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...
. It was a sauropod probably closely related to Apatosaurus
Apatosaurus
Apatosaurus , also known by the popular but scientifically deprecated synonym Brontosaurus, is a genus of sauropod dinosaur that lived from about 154 to 150 million years ago, during the Jurassic Period . It was one of the largest land animals that ever existed, with an average length of and a...
. It is known from a single site from the lower Morrison Formation
Morrison Formation
The Morrison Formation is a distinctive sequence of Late Jurassic sedimentary rock that is found in the western United States, which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone and limestone and is light grey, greenish...
, dating to about 154 million years ago. It grew up to 21 metres (68.9 ft) long.
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...
, E. yahnahpin, was described by James Filla and Patrick Redman in 1994 as a species of Apatosaurus
Apatosaurus
Apatosaurus , also known by the popular but scientifically deprecated synonym Brontosaurus, is a genus of sauropod dinosaur that lived from about 154 to 150 million years ago, during the Jurassic Period . It was one of the largest land animals that ever existed, with an average length of and a...
(A. yahnahpin). The specific name is derived from Lakota
Lakota language
Lakota is a Siouan language spoken by the Lakota people of the Sioux tribes. While generally taught and considered by speakers as a separate language, Lakota is mutually understandable with the other two languages , and is considered by most linguists one of the three major varieties of the Sioux...
mah-koo yah-nah-pin, "breast necklace", a reference to the pairs of sternal ribs that resemble the hair pipe
Hair pipe
A Hair Pipe is a term for a wide slim bead, more than 1.5 inches wide, which were popular with American Indians, particularly from the Great Plains and Northwest Plateau....
s traditionally worn by the tribe. 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...
is TATE-001, a relatively complete postcrania
Postcrania
Postcrania[p] in zoology and vertebrate paleontology refers to all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g...
l skeleton found in Wyoming
Wyoming
Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
, in the lower Morrison Formation
Morrison Formation
The Morrison Formation is a distinctive sequence of Late Jurassic sedimentary rock that is found in the western United States, which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone and limestone and is light grey, greenish...
. More fragmentary remains have also been referred to the species.
A re-evaluation by Robert T. Bakker
Robert T. Bakker
Robert T. Bakker is an American paleontologist who helped reshape modern theories about dinosaurs, particularly by adding support to the theory that some dinosaurs were endothermic...
in 1998 found it to be more primitive, and so Bakker coined the new generic name Eobrontosaurus, derived from Greek eos, "dawn", and Brontosaurus, the original generic name of Apatosaurus excelsus. It has been argued that Eobrontosaurus yahnahpin actually belongs within Camarasaurus
Camarasaurus
Camarasaurus meaning 'chambered lizard', referring to the hollow chambers in its vertebrae was a genus of quadrupedal, herbivorous dinosaurs. It was the most common of the giant sauropods to be found in North America...
, although this has been questioned. According to Bakker Eobrontosaurus was a member of the Diplodocidae, more especially the Apatosaurinae.
External links
- Eobrontosaurus in the Dinosaur Encyclopedia at DinoRuss' Lair