Edmontonia
| Edmontonia | ||||||||||||
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Live reconstruction of Edmontonia in the Royal Tyrrell Museum . |
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| Temporal occurrence | ||||||||||||
| Upper Cretaceous (middle Campanium to Maastrichtian ) | ||||||||||||
| 80.6 to 66 million years | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Edmontonia | ||||||||||||
| Sternberg , 1928 | ||||||||||||
| species | ||||||||||||
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Edmontonia is a genus of pelvic dinosaur . It is counted within the Ankylosauria to the Nodosauridae and lived in the Upper Cretaceous in North America.
features
Edmontonia reached a length of around 6 to 7 meters. He had the usual build of the ankylosauria with a stocky trunk and powerful limbs, he moved quadruped (on all fours). As with all ankylosauria, the top of the head, neck, torso and tail were covered with armor made of bone plates (osteoderms). The plates on the neck, which were rectangular and very wide, were noticeable. In addition, bony thorns covered the animals' flanks. As with all Nodosauridae, the tail did not end in a bony club.
The skull was around 49 centimeters long and, as with all Nodosauridae, relatively narrow. It was also armored on the top, and the cheek was also covered by a bone plate. The small, leaf-shaped teeth were adapted to a plant-based diet. In contrast to many older, more primitive Nodosauridae, the bony palate was well developed and the premaxillary (the foremost bone of the upper jaw) toothless.
Discovery and naming
Fossil remains from Edmontonia - including several complete skulls and large parts of the postcranial skeleton - have been found in numerous locations in North America, such as the US states of Montana , South Dakota , Wyoming and Texas , but also in the Canadian province of Alberta and Alaska . The name is derived from the Edmonton Formation in southeastern Alberta, not from the city of Edmonton . The finds from Edmontonia are dated to the Upper Cretaceous (middle Campanian to Maastrichtian ) to an age of around 80 to 66 million years.
Systematics
The type species is E. longiceps , which was first described in 1928 , and in 1930 a second species was described with E. rugosidens . This is occasionally in its own genus ( Chassternbergia ). The two types differ, among other things, in the proportions of the skull. A third species, described in 2000 as E. australis on the basis of some bone plates , is known as the nomen dubium . However, the various fossil finds suggest the existence of other, so far not described species of the genus Edmontonia . The Denversaurus described in 1988 is, according to today's knowledge, a synonym for E. longiceps .
Edmontonia is counted within the Ankylosauria in the group of Nodosauridae . Its closest relative is likely Panoplosaurus be, together they form an unnamed clade more sophisticated nodosauridae who only lived at the end of the Cretaceous period and the mass extinction disappeared of the dinosaurs 66 million years ago.
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.
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 , pp. 238-239, online .