Coelurosaurs are some of the most primitive of all the dinosaurs. It is from them that we get Tyrannosaurus and other giant meat-eaters.
Type: Primitive theropod
Size: 2-3m long
Diet: Carnivore
Predators: Large land reptiles like Postoschus
Lived: Mid Triassic to Early Jurassic, 230-200 million years ago.
Around 230 million years ago the first dinosaur fossils started to be found in places such as South America, Madagascar and Europe. These dinosaurs were much smaller than their later descendents and can be divided into two groups: The prosauropod dinosaurs, which are the primitive vegetarian forerunners of sauropods such as Diplodocus, and the more common coelurosaurs which were two-legged meat-eaters that would later evolve into giants such as Tyrannosaurus and Allosaurus.
The Triassic coelurosaur dinosaurs were small, nimble and built to survive in the harsh Triassic landscape. Unlike many of the four-legged lumbering reptiles around them, the coelurosaurs could use their two legs to travel at speed and to manoeuvre themselves out of dangerous situations. Their light skulls, long snout and flexible necks were ideal for hunting small animals such as insects, amphibians and other reptiles but the coelurosaurs could also live by scavenging when times were hard.
The arrival of the coelurosaur dinosaurs was a landmark in evolution. They quickly evolved into newer and larger species and spread themselves around the globe until, by the start of the Jurassic period, the dinosaurs dominated the land. The coelurosaurs helped found a dynasty that produced the largest and most feared land predators of all time. After the giant extinction event of 65 million years ago the only Earthly legacy of the dinosaurs are the birds which split from the coelurosaur dinosaurs sometime during the Late Jurassic period.
译文:
回到恐龙时代：暴龙的始祖--虚骨龙
虚骨龙是最原始的恐龙之一。我们熟知的暴龙和其他巨型食肉龙都是从它们演变而来的
门类：原始兽脚亚目食肉恐龙
尺寸：2至3米长
食性：肉食
天敌：大型陆地爬行动物，例如波斯特鳄
时代：三叠纪中期至侏罗纪早期，距今2亿3000万至2亿年
大约2亿3000万年前，第一颗恐龙化石在南美洲、马达加斯加和欧洲出现了。这些恐龙比由它们派生出的恐龙小得多，它们可以被分成两类：一种是蜥蜴类爬行恐龙，它们是最初的素食主义者，和后来的梁龙一样，另一种是更为常见的虚骨龙类，它们多为靠两条腿行走的肉食者，也就是它们后来演变为像暴龙和异龙这样的巨型恐龙的。
三叠纪时期的恐龙体型都比较小，动作敏捷，能够在荒芜的三叠纪中生存。不同于一些四腿的、动作迟缓的爬行动物，虚骨龙可以用它们的双腿迅速移动，成功脱离危险。它小巧的头，长长的嘴巴和灵活的颈部让它轻松的捕获小动物，例如昆虫、两栖动物和其他爬行动物，但是当没有食物摄入时，虚骨龙也可以靠净化自身来支撑一段时间。
虚骨龙类的出现是生物进化的一个里程碑。它们迅速的进化成为更新、更大的物种，并且在地球的每个角落都有出现，从侏罗纪时代开始，恐龙就掌管了整个陆地。虚骨龙类创建了一个王朝，专门诞生那个时期体积最大，最恐怖的陆上掠食者。在6500万年前，巨型生物不幸灭绝，存活下来的只有在侏罗纪末期从虚骨龙类衍生出的鸟类，它们是那个时期留给我们的宝贵遗产。