Ankylosaurus
| Ankylosaurus | ||||||||||||
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Live reconstruction of the Ankylosaurus |
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| Temporal occurrence | ||||||||||||
| Upper Cretaceous (Upper Maastrichtian ) | ||||||||||||
| 69.9 to 66 million years | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Ankylosaurus | ||||||||||||
| Brown , 1908 | ||||||||||||
| Art | ||||||||||||
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Ankylosaurus is a genus from the group of bird basin dinosaurs (Ornithischia) from the Upper Cretaceous North America. He is namesake and at the same time one of the largest and youngest representatives of the ankylosauria .
features
Ankylosaurus reached a length of 8 to 9 meters and an estimated weight of 3.5 tons. Like all ankylosaurs, it was a quadruped (moving on all fours) dinosaur with stocky feet ending in wide hooves. The back legs were a little longer than the front legs.
Armor and tail lobe
Like all ankylosaurs, it had armor made of bone plates ( osteoderms ) on its trunk , which protected it against attackers. These bone plates were embedded in the skin and varied considerably in size, there were wide, flat plates and narrow, round bumps. These plates were attached in horizontal rows to the neck, torso and hips of the animal, with the small bumps protecting the areas between the plates. In addition, the limbs and tail could have been protected by small plates.
The tail of Ankylosaurus ended like that of most representatives of the Ankylosauridae in a bony tail lobe. It was connected to the last of the caudal vertebrae, and strong tendons provided the mobility of this club, which could even shatter bones and probably be used for defense.
skull
The skull of Ankylosaurus was massive and massive (55 centimeters long, 70 centimeters wide) and, like all ankylosaurs, housed only a very small brain . The snout ended in a broad, toothless horned beak. The teeth were relatively small and leaf-shaped and adapted to a vegetable diet. The top of the skull was also covered with plates of bone, even the eyelids were protected by two plates. At the back of his head he had two horns protruding backwards, and a horn-like outgrowth protruded from each cheek.
Way of life
From the small brain, researchers deduce a restricted behavioral repertoire. The animals are likely to have been mostly loners. It is possible, however, that they were at times loosely socialized with other herbivores in herds or joined them for hikes.
The physique was not geared towards fast movements. Ankylosaurus was not a flight animal and presumably defended itself by flattening itself on the ground to show the attacker only its shell and not its soft underside. If the attacker was within range, he could have attacked with his tail club. The strong armor and the tail lobe could also have been important in fights between conspecifics. The high stability of the bone plates could also have served to ward off tail-club blows from conspecifics, for example in the fight for the mating privilege.
Ankylosaurus , like all ankylosaurs, was a herbivore. The small teeth were not suitable for thorough chewing, which is why further decomposition of the food took place in the large digestive tract.
Discovery and naming
Ankylosaurus fossil record was discovered in North America, the genus was first described by Barnum Brown . The name means "curved" or "stiffened lizard", the only species and thus type species is A. magniventris . Finds are known so far from Montana and Wyoming in the USA and Alberta in Canada . Three complete skulls and parts of the postcranial skeleton were found, but parts of the body structure of Ankylosaurus are not known. The finds are dated in the Upper Cretaceous Period (late Maastrichtian ) to an age of 69 to 66 million years and thus immediately before the extinction of the dinosaurs.
Systematics
Ankylosaurus is one of the Ankylosauridae within the Ankylosauria . Together with Euoplocephalus , a somewhat older dinosaur also known from North America, it forms an unnamed clade within the Ankylosaurinae, the more highly developed Ankylosauridae.
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.
- David E. Fastovsky , David B. Weishampel: The Evolution and Extinction of the Dinosaurs. 2nd edition. Cambridge University Press, Cambridge 2005, ISBN 0-521-81172-4 .
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. 234-235, online .
