Pinacosaurus
Pinacosaurus | ||||||||||||
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Skeletal reconstruction of Pinacosaurus |
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Temporal occurrence | ||||||||||||
Upper Cretaceous (late Santonium to Middle Campanium ) | ||||||||||||
85.2 to 76.4 million years | ||||||||||||
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Pinacosaurus | ||||||||||||
Gilmore , 1933 | ||||||||||||
species | ||||||||||||
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Pinacosaurus was a genus of pelvic dinosaurs from the group of Ankylosauria . She lived in the Upper Cretaceous in East Asia.
features
From pinacosaurus mainly subadulter animals were found which had a length of 1.5 meters. The fossil material of adults is poorer, they are likely to have reached a length of 5 meters. Pinacosaurus moved quadruped (on all fours) and was rather lightly built compared to other Ankylosauridae . As with all ankylosaurs, the trunk was covered with armor made of bone plates, and bony thorn humps offered additional protection. As with many Ankylosauridae, the tail ended in a bony club, which was presumably used to ward off enemies.
The skull (31 centimeters long in adult animals) is primarily characterized by the additional openings in the area of the nostrils, which are otherwise not found in any ankylosaurs. The first specimen found had a pair of additional openings; in animals found later, four and five pairs of openings have also been described. The exact function of these openings is controversial. The snout ended in a round, toothless horned beak. As with all ankylosaurs, the teeth were small and adapted to a vegetable diet.
Discovery and naming
Pinacosaurus is one of the dinosaurs discovered in the Gobi Desert in the 1920s by an expedition initiated by the American Museum of Natural History . The first description dates from 1933, the name Pinacosaurus means "plank lizard". In addition to the original finds in the Mongolian region of Ömnö-Gobi-Aimag , finds were later made in the Chinese provinces of Inner Mongolia and Shandong . Type species is P. grangeri ; In the 1990s, P. mephistocephalus was described as a second species that differs, among other things, in the number of holes next to the nostrils. The finds are dated in the Upper Cretaceous (late Santonium to Middle Campanium ) to an age of approx. 85 to 76 million years.
Systematics
Pinacosaurus is counted within the Ankylosauridae in the group of Ankylosaurinae, where it is counted to an unnamed clade of Asian genera, which also includes Saichania , Talarurus and Tianzhenosaurus . According to phylogenetic studies by Vickaryous et al. the genus could be paraphyletic with respect to Tianzhenosaurus , since P. mephistocephalus is more closely related to it than to P. grangeri .
literature
- Matthew K. Vickaryous, Teresa Maryańska , David B. Weishampel : Ankylosauria. In: David B. Weishampel, Peter Dodson , Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. 2004, ISBN 0-520-24209-2 , pp. 363-392.
Web links
Individual evidence
- ^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , p. 232 ( online ).