侏罗纪搏击俱乐部 第72期:巨齿鲨竟无法转弯

 　　Megalodon, fossils are found in the kind of geologic 1 deposits that form pretty close to shore.

　　能在离海岸非常近的地质沉淀物中，发现巨齿鲨的化石。
　　So, as far as we know, it was not a deep water kind of species or an open ocean, we call pelagic species.
　　所以就我们所知，它不是我们称作远洋物种的深海物种或是外海物种。
　　And that makes sense because its prey 2, things like marine 3 mammals and other large marine vertebrates that would have shared its ecosystem,这合情合理，因为它的猎物，像是海洋哺乳类动物和其它大型海洋脊椎动物，这些和它在同一生态系统的生物，probably lived in coastal 4 environments where there was up welling and more nutrient 5 supply in a biologically richer environment.
　　很可能生活在海岸环境里，那里有涌升流是个有着更多营养供应的生态上更富有的环境。
　　It takes a lot of hundred pound seals to feed a 50 ton Megalodon.
　　要想填饱五十吨巨齿鲨的肚子得要很多头上百磅重的海豹。
　　He's not gonna waste his time chasing those hors d'oeuvres.
　　它不会把时间都浪费在追逐这些小点心身上。
　　He's out looking for whales and giant squid and other large sharks.
　　它要去寻找鲸和巨乌贼以及其它大鲨鱼。
　　Megalodon is such a monstrous 6 shark.
　　巨齿鲨真是个可怕的鲨鱼。
　　It is estimated that he had to eat one fiftieth of his own body weight each day.
　　据估计它每天要吃下的食物达到自己体重的五十分之一。
　　That means everyday Megalodon needed to find food equivalent to the size and weight of an elephant.
　　那意味着巨齿鲨每天要找到的食物大小和重量相当于一头大象。
　　To do this, it would employ hunting skills honed over millions of years, skills still used by Great Whites today.
　　要想做到这点，它就需要数百万年磨练出来的狩猎技巧，这些今天仍是大白鲨的杀手锏。
　　When Megalodon hunted, it would probably stalk prey, perhaps from below.
　　当巨齿鲨狩猎时，它会跟踪猎物，可能是从下方。
　　It would seek the largest prey probably available to it.
　　它会寻找能找到的最大猎物。
　　Once it selected a prey item it would start accelerating towards it, and this would not be an explosive, short distance acceleration 7, it'd be acceleration over a fairly long distance.
　　一旦确定了目标它就会加速冲过去，这不会是短距离爆发性的冲刺，是在相当长距离上的加速。
　　When it made its final rush, reached its peak speed it really couldn't make a sharp turn.
　　当到了冲刺末端，达到最高速度时它根本没有办法做急转弯。
　　If the prey darted 8 to one side, it couldn't follow as easily as smaller fish could.
　　如果猎物冲向一侧，它没法像较小的鱼类那样轻易地跟上。
　　Comparing the tooth size of the Megalodon and a Great White shark speaks volumes.
　　把巨齿鲨的牙齿大小跟大白鲨的进行比较就说明了很多。
　　This is a bottom tooth of a Great White, probably a specimen 9 that was about 13 to 15 feet long.
　　这是一颗大白鲨下面的牙齿，样本体长大概四米左右。
　　This is its prehistoric 10 cousin, Megalodon, and you can see a little discrepancy 11 in the tooth size here.
　　这是它的史前亲戚，巨齿鲨，你能在这里看出一点牙齿大小的差异。
　　And to add to their lethal 12 ability, they had an endless supply of these knife-like teeth.
　　为这致命能力添砖加瓦的，还有它们有无限量的这种刀一般的牙齿的供应。
　　We know that, in some extreme cases, sharks in captivity 13 in aquariums 14 will replace each tooth in each position on the jaw 15 every maybe 8 to 10 days.
　　我们知道，在一些极端情况下，在水族馆里面豢养的鲨鱼大概每八到十天就会换掉口中各处的所有牙齿。
　　They will literally 16 go through tens of thousands of teeth per shark in a single lifetime, that's one of the really important reasons why shark teeth are so common in the fossil record.
　　在每条鲨鱼的生命历程中确实会长出上万颗牙齿，这也是鲨鱼牙齿在化石记录中非常普遍的原因之一。