Tyrannosaurus(redirected from Albertosaurus megagracilis)
Also found in: Dictionary, Thesaurus.
Tyrannosaurus(tīrăn'ōsôr`əs, tĭr–) [Gr.,=tyrant lizard], member of a family, Tyrannosauridae, of bipedal carnivorous saurischian dinosaursdinosaur
[Gr., = terrible lizard], extinct land reptile of the Mesozoic era. The dinosaurs, which were egg-laying animals, ranged in length from 2 1-2 ft (91 cm) to about 127 ft (39 m).
..... Click the link for more information. characterized by having strong hind limbs, a muscular tail, and short forelimbs. Tyrannosaurids are theropods, having three toes on the hind feet. The oldest known tyrannosaurids lived approximately 120 million years ago. Fossilized bones have been found in Asia, North America, and Australia. The family includes Albertosaurus, Tarbosaurus, and Tyrannosaurus.
The best known species is the huge North American Tyrannosaurus rex, which lived around 70 million years ago. The largest were an estimated 39 ft (12 m) in total length and weighed around 10 tons. They had an elongated skull and large, spike-shaped teeth in jaws that could open to a 4-ft (122-cm) gape. Like the other tyrannosaurids, the short forelimbs had two fingers armed, like the three digits of the powerful hind limbs, with sharp, curved claws; on the foot was a spurred toe not reaching to the ground. T. rex is believed to have existed only for a short time in the late Cretaceous period and to have dominated the North American continent at that time; fossil remains have been found in the W United States.
For many years T. rex was believed to be the largest carnivorous dinosaur, but this honor was challenged by the 1995 discovery of the 42.6-ft (13-m) Giganotosaurus carolinii in Patagonia, the 1996 discovery of the 45-ft (13.7-m) Carcharodontosaurus saharicus in the Moroccan Sahara, and subsequent finds. Remains of a second Tyrannosaurus species, T. bataar, have been found in Mongolia. It was a contemporary of T. rex, but was somewhat smaller and had a comparatively smaller head and shorter arms.
a genus of gigantic carnivorous dinosaurs of the superfamily Carnosauria. The tyrannosaur, which reached lengths of 15 m and more and stood more than 6 m tall on its hind legs, was the largest terrestrial predator in history. It had a massive skull (up to 1.5 m in length) and powerful daggerlike teeth. Its strong hind legs and powerful tail helped support the body, while its forelimbs were reduced to short appendages. The tyrannosaur was one of the last dinosaurs to live on the earth. Its remains have been discovered in Upper Cretaceous deposits of North America. The tyrannosaur was related to the tarbosaur.