Proceratosaurus
| Proceratosaurus | ||||||||||||
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Holotype of Proceratosaurus |
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| Temporal occurrence | ||||||||||||
| Middle Jurassic ( Bathonium ) | ||||||||||||
| 168.3 to 166.1 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Proceratosaurus | ||||||||||||
| Huene , 1926 |
Proceratosaurus is a genus theropod dinosaur from the group of Coelurosauria . Only the type species Proceratosaurus bradleyi belongs to this genus.
features
Proceratosaurus was a small, light, bipedal carnivore about three meters long . So far, only one skull with a jawbone is known, which comes from the Middle Jurassic layers ( Bathonium ) of the Great Oolite in Gloucestershire , England . Although the top of the skull is very incomplete, a head ornament was proven. Most of the time, a small horn is suspected that sat over the nostrils - but it could also be a crest, such as is found in Monolophosaurus . The skull is lightly built overall.
The teeth of the front half of the jaw are much smaller and more conical in shape than the teeth of the back of the jaw; the same feature is otherwise only found in the North American coelurosaur Ornitholestes .
Systematics
The fossils were originally attributed to Megalosaurus in 1910 by Arthur Smith Woodward , who named the animal Megalosaurus bradleyi . In 1926 Friedrich von Huene assigned the bones to a separate genus within the Ceratosauria , which he named Proceratosaurus . Proceratosaurus means "before the horned dinosaur", as von Huene considered the animal to be a forerunner of the Ceratosaurus , which also had a nasal horn. Later phylogenetic studies have shown that it belongs to the Coelurosauria - it could be more closely related to Ornitholestes hermanni (Paul, 1988). Together with Gasosaurus constructus , he is geologically the oldest known representative of this group. According to a new study, Proceratosaurus is the oldest member of the Tyrannosauroidea .
Gregory S. Paul assigned a brain skull (Neurocranium) to this genus in 1988, which is known as Piveteausaurus divesensis , and named the new species Proceratosaurus divesensis . The phylogenetic classification of Piveteausaurus is, however, controversial, and the thesis of a closer relationship with Proceratosaurus is doubted by most researchers.
Individual evidence
- ↑ a b Oliver WM Rauhut , Angela C. Milner , Scott Moore-Fay: Cranial osteology and phylogenetic position of the theropod dinosaur Proceratosaurus bradleyi (Woodward, 1910) from the Middle Jurassic of England. In: Zoological Journal of the Linnean Society. Vol. 158, No. 1, 2009, ISSN 0024-4082 , pp. 155-195, doi : 10.1111 / j.1096-3642.2009.00591.x .
- ^ Friedrich von Huene: The Carnivorous Saurischia in the Jura and Cretaceous Formations, principally in Europe. Revista del Museo de La Plata. Vol. 29, 1926, pp. 35-167 ( PDF 44.5 MB), pp. 69 f.
- ^ Gregory S. Paul : Predatory Dinosaurs of the World. A complete illustrated guide. Simon & Schuster, New York NY et al. 1988, ISBN 0-671-61946-2 , pp. 304-305.
