The result, once natural selection had done its work over the course of millions of years, was the now familiar cast of Allosaurus and Tyrannosaurus rex.

结果，历经数百万年间的自然选择，形成了我们今日熟知的异特龙和雷克斯霸王龙族群。

The Allosaurus was a meat eater.

异特龙是肉食动物。

The Allosaurus walked on two feet, but was slow. The Allosaurus could run.

异特龙是两条腿走路，但走的很慢，它也能跑。

Allosaurus was the top predatory dinosaur of the late Jurassic period in North America.

异龙是最大的掠夺性恐龙的晚侏罗纪期间在北美地区。

Photo Gallery: Jurassic Period An Allosaurus tramps through a Mesozoic-era forest in this artist's depiction.

侏罗纪时代图片集。一只古生异龙践踏通过一个中生代时期的森林在这方面艺术家的写照。

Allosaurus was a powerful predator that walked on two powerful legs, had a strong tail. The Allosaurus hunted in groups.

异特龙是个凶猛的捕食者，它有着强劲的后腿和健壮的尾巴，捕猎时是成群出击。

Photo Gallery: Jurassic Period Ghosts of an earlier age, an Allosaurus and a Stegosaurus brace for battle at the Denver Museum in Colorado.

侏罗纪时代图片集。幽灵的较早的时期，古生异龙和剑龙振奋精神战斗在丹佛博物馆在科罗拉多州。

Suggestions that they were the direct descendants of theropod dinosaurs (a group of bipedal meat-eaters that include Allosaurus, Velociraptor and Tyrannosaurus) caused quite a flap.

有人说它是兽脚恐龙的后代（兽脚恐龙是一群食肉的两足恐龙，其中包括异龙、迅猛龙与暴龙），这引起了学界很大的注意。

The result, once natural selection had done its work over the course of millions of years, was the now familiar cast of Allosaurus, Diplodocus, Triceratops and Tyrannosaurus rex.

结果，历经数百万年间的自然选择，形成了我们今日熟知的异特龙、梁龙、三角龙和霸王龙族群。