The family of tyrannosaurs includes the famous Tyrannosaurus rex as well as other large carnivores such as Albertosaurus and Tarbosaurus. They evolved in the late Cretaceous and their large size made them the top predators of the time. Like human beings, tyrannosaurs went through an adolescent growth spurt, increasing greatly in height and weight until they approached sexual maturity. Thereafter they grew much more slowly until they reached their final size. Tyrannosaur fossils are found in Asia and North America, through their ancestors also lived in Europe.
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Evolutionary arms race
Tyrannosaurs and horned dinosaurs were in a predator prey relationship for over 65 million years.
Tyrannosaurs and horned dinosaurs were in a predator prey relationship for over 65 million years.
Pack-hunting tyrannosaurs?
Did tyrannosaurs such as Albertosaurus hunt in packs or alone?
This programme was originally shown in 2000. The fossils described in the clip have since been definitively identified as Albertosaurus.
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Additional data source: Animal Diversity Web
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Cretaceous period
Cretaceous-Tertiary mass extinctionTyrannosauridae (or tyrannosaurids, meaning "tyrant lizards") is a family of coelurosaurian theropod dinosaurs which comprises two subfamilies containing up to six genera, including the eponymous Tyrannosaurus. The exact number of genera is controversial, with some experts recognizing as few as three. All of these animals lived near the end of the Cretaceous Period and their fossils have been found only in North America and Asia.
Although descended from smaller ancestors, tyrannosaurids were almost always the largest predators in their respective ecosystems, putting them at the apex of the food chain. The largest species was Tyrannosaurus rex, one of the largest known land predators, which measured up to 13 metres (43 ft) in length[citation needed] and up to 5,654 kilograms (6.23 short tons) in weight. Tyrannosaurids were bipedal carnivores with massive skulls filled with large teeth. Despite their large size, their legs were long and proportioned for fast movement. In contrast, their arms were very small, bearing only two functional digits.
Unlike most other groups of dinosaurs, very complete remains have been discovered for most known tyrannosaurids. This has allowed a variety of research into their biology. Scientific studies have focused on their ontogeny, biomechanics and ecology, among other subjects. Soft tissue, both fossilized and intact, has been reported from one specimen of Tyrannosaurus rex.
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Deadly dinosaurs
More dinosaurs have been discovered in the last two decades than the past 200 years.
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