Around 100 million years ago, South America was home to the biggest dinosaur that has ever walked the Earth. Argentinosaurus may have stood as tall as 21 metres (70 feet) and measured an enormous 35 metres (115 feet) in length.
At this size, Argentinosaurus probably shook the ground as it moved. Palaeontologists estimate that it may have weighed as much as 75 to 100 tonnes.
Social animal
Argentinosaurus was not a solitary animal. It probably moved in herds of around 20, stripping vegetated areas of leaves, seed and fruit before moving on to find a new place to graze.
It's difficult to believe that any animal ever dared attack this gigantic creature. But one daring and vicious creature did. Argentinosaurus was stalked by a truly awesome predator called Giganotosaurus.
Big and mean
This distant relative of Allosaurus measured 14 metres (45 feet) in length and weighed around 6 to 8 tonnes. Its skull alone was over 1.6 metres long and lined with rows of needle-sharp teeth.
While it was not as gigantic as its prey, Giganotosaurus' overall size makes it the largest carnivore that has ever lived. South America in the Early Cretaceous was the stage for the ultimate hunt: the largest predator ever, stalking the largest prey of all time.
Giganotosaurus probably hunted Argentinosaurus in packs of six or more. They would have singled out individuals that were young, weak or isolated from the herd and pursued them relentlessly, perhaps taking turns to bite and weaken their prey until they were exhausted.
Thrill of the chase
Giganotosaurus had powerful jaws that would have inflicted traumatic damage on their unlucky victims.
When the time was right, the pack of Giganotosaurus went in for the kill, gorging themselves in a frenzied binge. After an Argentinosaurus steak, Giganotosaurus would not have needed to eat for weeks afterwards.
Fast-moving prey
The plains and valleys of South America in the Early Cretaceous were also home to Diplodocus-like dinosaurs called Andesaurus, which may also have been preyed upon by Giganotosaurus. Large, fast-moving dinosaurs called iguanodonts also fed on vegetation in the forests and woodland.
Master of the skies
In the sky, Pteranodon used its membranous wings to soar on air currents called thermals. But these creatures were not quite masters of the skies. Pteranodon would have crossed flight paths with Ornithocheirus, the biggest flying animal of all time. Ornithocheirus boasted a wingspan of 40 feet, equivalent to that of a small aeroplane.
Ornithocheirus fed by swooping down over lakes, dipping its beak into the water and snatching fish with its razor sharp teeth.
译文:
陆地上的巨兽－－－早期白垩纪时代的南美洲
大约100百万年前，地球上体形最大的恐龙就栖息在南美洲的陆地上。 阿根廷龙站起来的高度达到了21米（70英尺），经过测量，它体长达到了35米（115英寸）。
由于它如此庞大的体积，当阿根廷龙行走时很可能地面也会震动。据估测，阿根廷龙的体重最轻为75吨，最重达到了100吨。
群居动物
阿根廷龙不是一种喜欢单独行动的动物。它们会聚集在一起，大约20只左右，成群结队地活动，一起吃光生长出来的叶子，种子和果实后，再去找下一个新栖息地。
很难想象有什么东西敢去袭击这种庞然大物。但是有一种胆大而且凶狠的动物就敢这么做。这个可怕的猎食者使阿根廷龙受到了威胁，它们的名字叫做巨兽龙。
巨大的猎物和不好对付的猎食者
跃龙这个远方亲戚长14米（45英尺），重约为6吨到8吨。单单它的头骨的长度就超过1.6米，上面还有一排排像针一样尖锐的牙齿。
虽然跃龙没有它的猎物那么庞大，但是拥有巨兽龙同身材的跃龙是世界上所有过数量最多的食肉动物。在早期白垩纪的南美洲完全就是一个捕猎场：数量最多的猎食者捕食体积最大的猎物的场景反复上演。
恐怖的追杀
巨兽龙的颚力量很大，可以给它们可怜的猎物造成致命的一击。
当一切就绪的时候，整群的巨兽龙就会发动一场屠杀，然后在狂乱中，巨兽龙享受了一吨美餐。在结束了阿根廷龙大餐之后，巨兽龙可以几个星期都不再需要吃东西。
敏捷的猎物
在早期白垩纪的南美洲还栖息着一种长得很像梁龙的恐龙，它们的名字叫做安第斯龙。它们同样是巨兽龙的猎物。这种被称为禽龙的巨大又敏捷的动物也是以森林为生的食草动物。
天空的主人
在天空，无齿翼龙用它们膜状的翅膀在暖气流中飞行。但它们并不是天空的主人。无齿翼龙会与鸟掌龙在天空中上擦身而过，鸟掌龙是有史以来最大的飞禽。打开双翼的鸟掌龙有40英尺长，相当一部小型飞机的长度。
鸟掌龙通过从空中俯冲到湖面进行猎食，将它们的嘴伸进水里，然后用它们锋利的牙齿捕捉水里的鱼。