Dilophosaurus
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| Dilophosaurus Fossil range: Early Jurassic | ||||||||||||||||
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| Image:Dilophosaurus.jpg Reconstruction of Dilophosaurus wetherelli
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D. wetherelli (Welles, 1954) (type) |
Dilophosaurus was a theropod dinosaur from the Early Jurassic Period. The name is (pronounced /daɪˌlɒfəˈsɔrəs/ ("dy-LOH-fo-sawr-us") meaning 'two-crested lizard', because it had two crests (Greek di meaning 'two', lophos meaning 'crest' and sauros meaning 'lizard') . The first specimens were described in 1954, but it was not until a decade later that the genus received its current name.
Dilophosaurus have appeared several times in popular culture, most prominently as the creature that eats Dennis Nedry in Jurassic Park. The creatures have also appeared in novels such as Carnosaur and numerous video games; the interpretations of Dilophosaurus in these adaptations are usually erroneous.
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[edit] History
The first Dilophosaurus specimens were discovered by Sam Welles in the summer of 1942.[1] The specimen was brought back to Berkeley for cleaning and mounting, where it was given the name Megalosaurus wetherilli.[2] Returning to the same formation a decade later to determine from which time period the bones dated, Welles found a new specimen not far from the location of the previous discovery. The specimens were later renamed Dilophosaurus, based on the double crest clearly visible in the new skeleton.[2][3]
[edit] Description
Dilophosaurus measured around 6 meters (20 ft) long and may have weighed half a ton. Fossils of the animal have been found at the Navajo Indian Reservation, just west of Tuba City, Arizona, USA. Just a few tens of feet below the level of the bones, large footprints of carnivorous dinosaurs were found and these may belong to Dilophosaurus. It lived in the Early Jurassic Period. Welles later redescribed the entire taxon in 1984, in a more comprehensive paper. Dilophosaurus may be a primitive member of the clade containing both ceratosaurian and tetanuran theropods. Alternatively, some paleontologists classify this genus as a large coelophysoid. Recent potential Dilophosaurus 'skin imprints', associated with a set of footprints, seemed to suggest that it had feathers but further study revealed these to be impressions of plant material.
[edit] Skull and crests
The most distinctive characteristic of Dilophosaurus was the pair of rounded crests on its skull, probably used for display. Studies by Rob Gay (2001) show that these crests may have been larger in one sex than in the other. Another curious skull feature was a notch behind the first row of teeth, giving it an almost crocodile-like appearance. This "notch" existed by virtue of a weak connection between the premaxillary and maxillary bones of the skull. This conformation led to the early hypothesis that Dilophosaurus scavenged off dead carcasses, with the front teeth being too weak to bring down and hold large prey. A similar notch is present in most other species of coelophysoid.
[edit] Species
There is another species of Dilophosaurus (D. sinensis), which may or may not belong to this genus. It is possibly closer to the bizarre Antarctic theropod Cryolophosaurus, based on the fact that the anterior end of the jugal does not participate in the internal antorbital fenestra and that the maxillary tooth row is completely in front of the orbit and ends anterior to the vertical strut of the lacrimal. This species was recovered from the Yunnan Province of China in 1987, with the prosauropod Yunnanosaurus and later described and named in 1993 by Shaojin Hu.
[edit] In popular culture
Dilophosaurus was prominently featured both in the 1993 movie Jurassic Park, and in the original novel by Michael Crichton. In the film version, Dilophosaurus has a retractable neck frill around its neck (much like a frill-necked lizard), and spits blinding poison, aiming for the eyes to blind and paralyze its prey. There is no evidence to support either the frill or the venom spitting,[4] which was acknowledged by Crichton as creative license.[5] In the film, Steven Spielberg also reduced Dilophosaurus's size to 3 feet tall and 5 feet long, much smaller than it should have been.
Jurassic Park merchandise, including toys and video games (such as Jurassic Park: Operation Genesis and the arcade games The Lost World: Jurassic Park and Jurassic Park III), often include Dilophosaurus. Another video game, ParaWorld, features a Dilophosaurus modeled after the ones in Jurassic Park. Yet another dinosaur-themed game, Jurassic Wars, featured a Dilophosaurus, which spat venomous saliva, just as described in the movie.
A Dilophosaurus is one of the main dinosaurs featured in John Brosnan's 1984 horror novel, Carnosaur, in which it kills a Member of Parliament.
Dilophosaurus was also featured in the documentary When Dinosaurs Roamed America, killing an Anchisaurus and scaring off a pack of Megapnosaurus.
[edit] References
- ^ Welles, Sam (2007). Dilophosaurus Discovered. ucmp.berkeley.edu. Retrieved on 2007-11-17.
- ^ a b Welles, Sam (2007). Dilophosaurus Details. ucmp.berkeley.edu. Retrieved on 2007-11-17.
- ^ Gay, Robert. (2001). "New specimens of Dilophosaurus wetherilli (Dinosauria: Theropoda) from the early Jurassic Kayenta Formation of northern Arizona". Western Association of Vertebrate Paleontologists annual meeting volume Mesa, Arizona: 1.
- ^ Bennington, J Bret (1996). "Errors in the Movie "Jurassic Park"". American Paleontologist 4(2): 4-7.
- ^ Crichton, Michael (1990). Jurassic Park. Alfred A. Knopf. ISBN 0-394-58816-9.
- Gay, R. (2001). "Evidence for sexual dimorphism in the Early Jurassic theropod dinosaur, Dilophosaurus and a comparison with other related forms". Journal of Vertebrate Paleontology 21(3): 53A.
- Hu, Shaojin (1993). "A note on a double-crested dragon (Dilophosaurus) fossil discovered in Jinning County, Yunnan Province." Gu Jizhui Dongwu Xuebao = Vertebr. PalAsiatica, 31 i.
- Welles, S. P. (1954). "New Jurassic dinosaur from the Kayenta formation of Arizona". Bulletin of the Geological Society of America 65: 591-598.
- Welles, S. P. (1984). "Dilophosaurus wetherilli (Dinosauria, Theropoda), osteology and comparisons." Palaeontogr. Abt. A: Paläozool., Stratigr., 185, 85-180.
[edit] External links
| Dinosaurs Portal |
cs:Dilophosaurus de:Dilophosaurus es:Dilophosaurus fr:Dilophosaurus it:Dilophosaurus wetherilli nl:Dilophosaurus ja:ディロフォサウルス pl:Dilofozaur pt:Dilofossauro simple:Dilophosaurus sk:Dilophosaurus fi:Dilophosaurus sv:Dilophosaurus zh:双脊龙
