Tyrannosaurus Rex
- Name meaning: Tyrant Lizard king
- average length: 12.3-13 m( 40-43 ft )
- maximum length: 13.2-13.87 m (44-45.7 ft )
- average weight: 9-9.2 tons
- maximum weight: 11-11.87 tons
- average height: 4-4.7 m (13-19 ft)
- maximum height: 5.5-6 m (18-22 ft)
- time period: 69.45-65 mya
- habitat: north America
- skull length: 144-158 cm (4.04-6.002 ft )
- bite force: 18000 psi
- tooth length: 30 cm 12 in.
Tyrannosaurus rex ( Tyrant lizard king ) is one of the most ferocious land predators ever to have existed. It is a relatively abundant theropod with more than 30 specimens of Tyrannosaurus rex have been identified, some of which are nearly complete skeletons. soft tissues and proteins have been reported in at least one of these specimens. The abundance of fossil material has allowed significant research into many aspects of its biology, including life history and biomechanics. The feeding habits, physiology and potential speed of Tyrannosaurus rex are a few subjects of debate. Its taxonomy is also controversial, with some scientists considering tarbosaurus bataar from Asia to represent a second species of Tyrannosaurus and others maintaining Tarbosaurus as a separate genus. Several other genera of North American tyrannosaurids have also been synonmized with Tyrannosaurus. Tyrannosaurus had a skull reaching 4-6 feet long. Tyrannosaurus had the highest bite force of any terrestrial animal becaise of it's massive jaws that were backed by huge muscles that allowed it to bite down with bone-crushing force. Tyrannosaurus had a bite force of 6,800 pounds per square inch while eating, with an estimated maximum of over 20,000 pounds per square inch during full on biting. It is very likely that Tyrannosaurus had some form of feathers covering its massive body as a lot of its relatives have been found to have them.
Size: The overall size of Tyrannosaurus is a state of debate, most estimates put it in the 38-42 foot (11-12.8 meters), 7-9 ton range. The most complete Tyrannosaurus specimen found (sue) measures 42 feet (12.8 meters) in length and weighs 7-9 tons. The average size for T-rex are about 40 feet (12 m) in length and 8-9 tons in weight. The maximum size for T-rex is 46 feet (14.6 meters) and 11 tons in weight based on C-Rex, F-Rex.
Arms: At 3 feet (1 meter) long, the arms of T-rex are tiny compared to the animal's 40+ foot (12+ meter) body. Despite their small size, theories suggest that the arms of T-rex could lift some 500 pounds. Scientists are unsure about what the arms were used for; but one theory is hunting in which it could have been adapted to grasp onto the back of Triceratops while pushing with its pectoral region, its large clawed feet would have given it better traction, its large head could have been used to tip the Triceratops over and its large mouth and bone piercing teeth would have made bites to the side more efficient and deadly. When the Triceratops had fallen over to its side, Tyrannosaurus would then bitten it at the rib cage; killing it. Krauss and Robinson would back up their proposal through physical analyses; finding that Tyrannosaurus moving at moderate could have generated enough force to topple Triceratops and would have only taken 2-3 seconds. The study states that a Tyrannosaurus impacting the Triceratops at a conservative estimated speed of 7.5 meters per second would have enabled it to topple Triceratops without injuring itself. But we still are not sure weather Tyrannosaurus used it's arms at all.
Speed: Tyrannosaurus' speed is a heavily debated subject. Estimates as low as 11 mph have been suggested, as well as estimates up to 45 mph. The most common top-speed suggested for an adult T-rex is in the 32 mph based on research done in 2012 - fast for an animal that outweighed the modern African elephant.