Tawa (dinosaur)
Tawa | ||||||||||||
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Temporal occurrence | ||||||||||||
Upper Triassic | ||||||||||||
215 to 213 million years | ||||||||||||
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Tawa | ||||||||||||
Nesbitt et al. , 2009 | ||||||||||||
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Tawa is a genus of theropod dinosaur from the central Upper Triassic of North America (215 to 213 mya ).
All known fossils come from the Chinle Formation in the US state of New Mexico . The only species is Tawa hallae , which Nesbitt et al. was first scientifically described and named. The generic name is a Hopi name for the pueblo sun god. The species addition honors the amateur paleontologist Ruth Hall, who found many of the fossils that formed the basis of the "Ghost Ranch Ruth Hall Museum of Paleontology".
In 2004 a partial skeleton was found, and in 2006 two almost complete skeletons. The discovery of this early dinosaur suggests that the first dinosaurs developed and spread from the ancient continent of Gondwana in what is now South America .
description
The holotype is most likely from a young animal. The intermaxillary bone looks similar to that of the Coelopysids . It is toothless. The skull differs from that of the neotheropods by the high upper jaw , as in Herrerasaurus . The slender body also looked like those of the Coelophysids. The teeth were small. It is estimated that the tawa was about 2 meters long.
discovery
The fossils were found in 2004 at Ghost Ranch ( New Mexico , USA ). The holotype, cataloged as GR 241, is a fairly complete skull and skeleton that came from a juvenile animal. At least seven other specimens were found in the Ghost Ranch, one of these animals is also almost complete. An isolated femur indicates that the adults were about 30% larger than juveniles. Studies show that the Tawa fossils are around 215 million years old. Tawa was described in 2009 by a team of American paleontologists at the American Museum of Natural History , led by Sterling J. Nesbitt . The description was published in the journal Science .
Systematics
A study showed that Tawa is more developed than previously known theropods, such as Eoraptor or Herrerasaurus . Tawa is provided as a sister taxon of the Neotheropoda .
Theropoda |
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supporting documents
- ↑ Sterling J. Nesbitt et al .: A complete skeleton of a Late Triassic saurischian and the early evolution of dinosaurs. In: Science . Vol. 326, No. 5959, 2009, pp. 1530–1533, doi : 10.1126 / science.1180350 , digital version (PDF; 2.78 MB)
- ↑ Maffly, Brian: New Mexico find sheds light on early dinosaur dispersal ( Memento of the original from December 13, 2009 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. December 10, 2009, Salt Lake Tribune
- ↑ New T. Rex Cousin Suggests Dinosaurs Arose in S. America National Geographic 10 December, 2009
- ↑ Airhart, Marc (10 December 2009), "New Meat-Eating Dinosaur age Evolutionary Tree" , Jackson School of Geosciences
- ^ Harmon, Katherine (December 10, 2009): "Newly Discovered T. Rex Relative Fleshes Out Early Dino Evolution"