Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK.
Science. 2010 Mar 26;327(5973):1613. doi: 10.1126/science.1187456.
Tyrannosaurids monopolized the apex predator niche in latest Cretaceous Laurasia. Unfortunately, the preceding 100-million-year tyrannosauroid lineage is poorly documented, and its fossil record is restricted to the northern continents. We report an Australian tyrannosauroid, represented by a pubis from the late Early Cretaceous of Victoria. This demonstrates that these extraordinarily successful predators were not restricted to Laurasia. The advanced morphology and small size of the specimen shows that tyrannosauroids with the characteristic short arms and robust skulls probably had a global distribution in the Early Cretaceous. Thus, a potentially cosmopolitan grade of small tyrannosauroids with a tyrannosaurid-like body plan preceded the Late Cretaceous rise of the colossal tyrannosaurids.
暴龙类在白垩纪晚期的劳亚古陆中垄断了顶级掠食者的生态位。不幸的是，此前 1 亿年的暴龙类谱系记录不佳，其化石记录仅限于北方大陆。我们报道了一种来自维多利亚州晚早白垩世的澳大利亚暴龙类，其代表是一块耻骨。这表明这些极其成功的掠食者并非仅限于劳亚古陆。该标本具有先进的形态和较小的体型，表明具有典型短臂和强壮头骨的暴龙类可能在早白垩世就已经在全球分布。因此，一种具有暴龙类身体形态的潜在世界性的小型暴龙类等级，可能在晚白垩世巨型暴龙类崛起之前就已经存在。
