Tyrannosaurus is the most famous dinosaur genus and a fixture in popular culture. Known colloquially as T. rex, the species Tyrannosaurus rex hails from what is now western North America. Some scientists consider the slightly older Tarbosaurus bataar from Asia to represent a second species of Tyrannosaurus, while others maintain Tarbosaurus as a separate genus. Like other tyrannosaurid theropods, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to the large and powerful hindlimbs, Tyrannosaurus forelimbs were small, and retained only two digits. Although other theropods rivaled or exceeded T. rex in size, it was the largest known tyrannosaurid and one of the largest known land predators, measuring over 12 meters (40 feet) in length and weighing as much as an elephant. Fossils of T. rex have been found in North American rock formations dating to the very end of the Cretaceous Period; it was among the last dinosaurs to exist prior to the Cretaceous-Tertiary extinction event. More than 30 specimens of T. rex have now been identified, some nearly complete, which has allowed significant research into many aspects of its biology, including its life history and biomechanics. However, the feeding habits and potential speed of T. rex remain controversial. Read the rest of this article: http://en.wikipedia.org/wiki/Tyrannosaurus _______________________________ Today's selected anniversaries: 1683: Great Turkish war: Polish troops led by Jan III Sobieski joined forces with a Habsburg army to defeat the Ottoman Empire at the Battle of Vienna. (http://en.wikipedia.org/wiki/Battle_of_Vienna) 1933: Leó Szilárd, waiting for a red light on Southampton Row in Bloomsbury, conceived of the idea of the nuclear chain reaction. (http://en.wikipedia.org/wiki/Le%C3%B3_Szil%C3%A1rd) 1942: The Laconia incident: A U-boat sank RMS Laconia with a torpedo off the coast of West Africa and attempted to rescue the passengers, which included some 80 civilians, 160 Polish and 268 British soldiers and about 1800 Italian POWs. (http://en.wikipedia.org/wiki/Laconia_incident) 1977: South African anti-apartheid activist Steve Biko was killed in police custody. (http://en.wikipedia.org/wiki/Steve_Biko) 1992: Abimael Guzmán, leader of the Peruvian Maoist guerrilla organization Shining Path, was captured in Lima. (http://en.wikipedia.org/wiki/Shining_Path) _____________________ Wikiquote of the day: "When I came back to my native country, after all the stories about Hitler, I couldn't ride in the front of the bus. I had to go to the back door. I couldn't live where I wanted. When I came back to my native country, after all the stories about Hitler, I couldn't ride in the front of the bus. I had to go to the back door. I couldn't live where I wanted. I wasn't invited to shake hands with Hitler, but I wasn't invited to the White House to shake hands with the President, either. -- Jesse Owens (http://en.wikiquote.org/wiki/Jesse_Owens)