香港旅遊 / 街拍 (045) 將軍澳廣場 會怪叫的 暴龍 Tyrannosaurus T. rex
4暴龍（學名：Tyrannosaurus；又名：霸王龍），目前唯一的有效種是模式種雷克斯暴龍（Tyrannosaurus rex），是一種巨型的肉食性恐龍，身長超過13公尺[1]，臀部高度約4公尺[2]，體重最大約6.8公噸[3]。暴龍生存於白堊紀末期的馬斯垂克階，距今約6700萬年到6500萬年[4]，是白堊紀-第三紀滅絕事件前最後的恐龍種群之一。化石分布於北美洲的美國、加拿大西部，分布範圍較其他暴龍科更廣；白堊紀晚期的北美洲西部是個獨立的拉臘米迪亞大陸。
有些科學家認為亞洲的勇士特暴龍（Tarbosaurus bataar）是暴龍屬的第二個有效種，而其他科學家則認為特暴龍是獨立的屬。除此之外，過去有許多暴龍科的種被歸類於暴龍屬，但目前多被認為是暴龍的異名，或被分類於其他屬。
如同其他的暴龍科恐龍，暴龍是二足、肉食性恐龍，擁有大型頭顱骨，並藉由長而重的尾巴來保持平衡。相對於牠們大而強壯的後肢和巨大的身體，暴龍的前肢非常小，但有研究發現具有十分發達的肌肉。長久以來，暴龍被認為只有兩根手指，但在2007年發現的一個完整的暴龍化石，顯示牠們也可能具有三根手指。暴龍被認為是種掠食動物，以大型食草恐龍為食，但也有少數科學家認為暴龍是種積極的食腐動物。雖然目前有其他獸腳亞目恐龍的體型與暴龍相當或更大，暴龍仍在巨型肉食恐龍名單之列，亦是最著名的陸地掠食動物之一，擁有肉食恐龍中最大的咬合力。[5]
目前已有超過30個雷克斯暴龍的標本被確認，包含幾具完整度很高的化石。暴龍的大量化石材料，使科學家們有足夠的資料研究暴龍生理的各個層面，包括生長模式與生物力學。有些研究人員還在標本上發現了軟組織與蛋白質。但暴龍的食性、生理機能以及移動速度仍在爭論中。
yrannosaurus (/tɨˌrænəˈsɔrəs/ or /taɪˌrænəˈsɔrəs/ ("tyrant lizard", from the Ancient Greek tyrannos (τύραννος), "tyrant", and sauros (σαῦρος), "lizard"[1])) is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex (rex meaning "king" in Latin), commonly abbreviated to T. rex, is one of the most well-represented of the large theropods. Tyrannosaurus lived throughout what is now western North America, which then was an island continent named Laramidia. Tyrannosaurus had a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the Maastrichtian age of the upper Cretaceous Period, 68 to 66 million years ago.[2] It was the last known member of the tyrannosaurids,[3] and among the last non-avian dinosaurs, to exist before the Cretaceous–Paleogene extinction event.
Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to its large and powerful hind limbs, Tyrannosaurus fore limbs were short but unusually powerful for their size and had two clawed digits. Although other theropods rivaled or exceeded Tyrannosaurus rex in size, it was the largest known tyrannosaurid and one of the largest known land predators. In fact, the most complete specimen measures up to 12.3 m (40 ft) in length,[4] up to 4 metres (13 ft) tall at the hips,[5] and up to 6.8 metric tons (7.5 short tons) in weight.[6] By far the largest carnivore in its environment, Tyrannosaurus rex may have been an apex predator, preying upon hadrosaurs, ceratopsians, and possibly sauropods,[7] although some experts have suggested the dinosaur was primarily a scavenger. The debate about whether Tyrannosaurus was an apex predator or scavenger was among the longest ongoing feud in paleontology; however, most scientists now agree that Tyrannosaurus rex was an opportunistic carnivore, acting as both a predator and a scavenger.[8] It is estimated to be capable of exerting one of the largest bite forces among all terrestrial animals.[9][10]
More than 50 specimens of Tyrannosaurus rex have been identified, some of which are nearly complete skeletons. Soft tissue 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 its 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, as some scientists consider Tarbosaurus bataar from Asia to be a second Tyrannosaurus species while others maintain Tarbosaurus is a separate genus. Several other genera of North American tyrannosaurids have also been synonymized with Tyrannosaurus.