Coloradisaurus
Encyclopedia
Coloradisaurus is a genus
of massospondylid
sauropodomorph dinosaur
. It lived during the Late Triassic
period (Norian
to Rhaetian
stages) in what is now La Rioja Province, Argentina
. It is known from the holotype
PVL 5904, nearly complete skull
. It was discovered and collected from the upper section of the Los Colorados Formation
. Originally named Coloradia by Jose F. Bonaparte in 1978, this name had already been assigned to a moth
, and so the animal was renamed. The genus was first named by David Lambert in 1983
and the type species is Coloradisaurus brevis. It may in fact be an adult specimen of Mussaurus
. Recent cladistic analyses by Yates (2007), Yates et al. (2010, 2011) and Novas et al. (2011) found that Coloradisaurus is basal
to the Glacialisaurus
-Lufengosaurus
clade within Massospondylidae
.
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 massospondylid
Massospondylidae
Massospondylidae is a family of massopod sauropodomorphs. Massospondylids are early sauropodomorph dinosaurs which existed in Asia, Africa and South America during the Late Triassic to the Early Jurassic periods...
sauropodomorph 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 Triassic
Late Triassic
The Late Triassic is in the geologic timescale the third and final of three epochs of the Triassic period. The corresponding series is known as the Upper Triassic. In the past it was sometimes called the Keuper, after a German lithostratigraphic group that has a roughly corresponding age...
period (Norian
Norian
The Norian is a division of the Triassic geological period. It has the rank of an age or stage . The Norian lasted from 216.5 ± 2.0 to 203.6 ± 1.5 million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.-Stratigraphic definitions:The Norian was named after the Noric Alps in...
to Rhaetian
Rhaetian
The Rhaetian is in geochronology the latest age of the Triassic period or in chronostratigraphy the uppermost stage of the Triassic system. It lasted from 203.6 ± 1.5 to 199.6 ± 0.6 million years ago...
stages) in what is now La Rioja Province, Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
. It is known from 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...
PVL 5904, nearly complete skull
Skull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
. It was discovered and collected from the upper section of the Los Colorados Formation
Los Colorados Formation
The Los Colorados Formation is a sedimentary rock formation found in La Rioja, Argentina. It has a Norian age , and is notable for its fossils of early dinosaurs, including the coelophysoid Zupaysaurus and the "prosauropods" Coloradisaurus, Lessemsaurus, and Riojasaurus.-Dinosaurs:Indeterminate...
. Originally named Coloradia by Jose F. Bonaparte in 1978, this name had already been assigned to a moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
, and so the animal was renamed. The genus was first named by David Lambert in 1983
1983 in paleontology
-Newly named dinosaurs:Data courtesy of George Olshevsky's dinosaur genera list and Dr. Jeremy Montague's dinosaur genus database.-New taxa:-Non-mammalian:...
and the type species is Coloradisaurus brevis. It may in fact be an adult specimen of Mussaurus
Mussaurus
Mussaurus was a genus of herbivorous prosauropod dinosaur that lived in southern Argentina during the Late Triassic Period, about 215 million years ago...
. Recent cladistic analyses by Yates (2007), Yates et al. (2010, 2011) and Novas et al. (2011) found that Coloradisaurus is basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
to the Glacialisaurus
Glacialisaurus
Glacialisaurus is a genus of massospondylid sauropodomorph dinosaur. It lived during the Early Jurassic period in what is now central Transantarctic Mountains of Antarctica. It is known from the holotype FMNH PR1823, a partial hind limb and from the referred material FMNH PR1822, a left...
-Lufengosaurus
Lufengosaurus
Lufengosaurus is a genus of prosauropod dinosaur which lived during the Early Jurassic period in what is now southwestern China.-Discovery and species:...
clade within Massospondylidae
Massospondylidae
Massospondylidae is a family of massopod sauropodomorphs. Massospondylids are early sauropodomorph dinosaurs which existed in Asia, Africa and South America during the Late Triassic to the Early Jurassic periods...
.