Megalodon, 50 tons of pure menace in the body of a monster shark, dwarfing today's Great White.
巨齿鲨，体重达五十吨，这怪兽般的鲨鱼无比凶残，让现在的大白鲨相形见绌。
Step by step, science expands the evidence to show that the ancient seas were the playground of these real life sea monsters.
一步步地，科学将揭示出证据表明古代海洋曾是这真实存在的海怪的游乐场。
They were the Earth's largest animals.
它们曾是地球上最大的动物。
New technology and forensic evidence helps paleontologists bring to life some of their final moments.
新的科技和现场证据如今帮助古生物学家们重现了它们生命中的最后时刻。
15 million years ago, it was the mid-Miocene era.
一千五百万年前，是第三纪中新统中期。
Earth was in the throes of tectonic upheaval.
地球正处于板块剧烈变化中。

Mountain ranges known today as the Himalayas, the Andes, and the Rockies soar skyward.
今天的喜马拉雅山脉，安第斯山脉和落基山脉，急剧隆起。
Global weather patterns changed, causing dramatic shifts around the world.
全球的气候模式改变了，引发了全世界范围的剧变。
But it was the sea that experienced the greatest change.
但是经历了最大改变的是海洋。
Powerful ocean currents carried nutrients from the depths of the Pacific Ocean creating a lush ecosystem.
强大的洋流携带着太平洋深处的养分创造出茂盛的生态系统。
Millions of new life forms flourished.
数百万种新的生命形式繁荣着。
Mammals that once roamed the land adapted to an aquatic life and evolve fins to take advantage of this new food source.
曾经在陆地游荡的哺乳动物适应了水中的生活，进化出鳍肢来利用这个新的食物来源。
But the peace of the surface was misleading.
不过水面的平静只是假象。
30 meters below a deep sea mammoth roamed these waters.
在三十米以下这些水域里游荡着一种深海巨兽。
And a new discovery brings it to life for the first time.
一个新发现让这一切第一次得见天日。
Information about deep sea giants is exceedingly rare.
深海巨兽的信息非常少。
But paleontologists, working on every continent, have uncovered something remarkable, and disturbing.
不过每个大洲的古生物学家们，都发现了一些非同寻常同样也引人恐慌的东西。
Thousands of whale bones, found in every corner of planet earth, different species, different sizes.
数千块鲸骨，出土于全球的每个角落，种类不同，尺寸各异。
But the whale bones all share one common characteristic: deep gashes driven into them with tremendous force.
但这些鲸骨都有一个共同特点：有巨大的力量在它们上面形成的深深的沟痕。