These leviathans are making a journey to nesting sites they've used for generations.
这些庞然大物正在前往它们世代繁衍的筑巢之地。
Developing inside them are hundreds of eggs.
在它们体内，上百个蛋已经发育成熟。
They're the future of a species that will be around for 15 million years, more than 75 times longer than humans have been on earth.
它们是这个已经在地球上存在了1500万年的物种的未来，比人类在地球生存时间的75倍还要多。
Yet each egg is no larger than a cantaloupe melon.
然而每一枚蛋还不及哈密瓜的大小。
I think it's a very beautiful idea that you have this little egg that's surprisingly small and out of it comes a baby Sauroposeidon that's about the size of a rabbit.
我觉得这非常美妙，这枚蛋如此小巧，会有一只只兔子大小的波塞冬龙从中破壳而出。
And in two or three decades, it's gonna be a 50-ton adult. But just why does this huge animal have such small eggs?
二三十年后，它会长成一只50吨重的成年恐龙。但为什么这么大的动物蛋却这么小呢？
Sauroposeidon eggs, like all eggs, are honeycombed with tiny pores to let oxygen in and carbon dioxide out.
波塞东龙的蛋，与其它的蛋一样都布满了让氧气进入和二氧化碳排出的微小气孔。
Bigger eggs need more air holes. But if they get too big, the shell collapses.
蛋的体积越大，需要的气孔也越多。但如果过于巨大，蛋壳就会坍塌。
That's why even today, no bird lays a larger egg than an ostrich, which weighs just over a kilogram.
这也就是为什么即使在今天也没有哪种鸟蛋能大过鸵鸟蛋的原因，而鸵鸟蛋也才重一千多克。
Each female lays about 500 eggs a season.
每一只雌性恐龙在生育季节大约会下500枚蛋。
The moment an egg hatches marks the beginning of a race for survival, a race virtually all of them will lose.
蛋孵化的那一刻就标志着生存竞赛的开始，这其实是一场没有胜者的竞赛。
Being a hatchling, you don't have horns, you don't have plates, you don't have any kind of armor on the body.
刚孵化的幼兽，没有角和鳞片，身体上没有任何甲壳。
Practically anything could gobble it up.
几乎任何生物都能将它一口吞下。
Thousands of defenseless hatchlings are let loose into a world of fierce predators.
数以千计没有保护的幼崽就这样来到了充满凶残肉食者的世界。
It's a brutal way to raise a family.
这种养育后代的方式非常残酷。
Sauropods were just trying to flood the environment with babies, just in the hopes that a few survive.
波塞东龙只是一直在疯狂产卵，希望少数能够存活下来。
