海豚科

系统重建分析支持海豚科和鼠豚科为单系发生，且两者构成姐妹群关系；

The phylogenetic reconstruction supported Delphinidae and Phocoenidae respective monophyletic groups , and proposed a sister relationship between these two families .

此外，分子生物学技术还被用于解决须鲸亚目和齿鲸亚目内科间以及科内种间的系统发生关系，特别是齿鲸亚目的海豚科、鼠豚科和淡水豚类。

In addition , molecular biological techniques have been applied to address phylogenetic relationships among families within the suborder Mysticeti or Odontoceti , and within families , especially within the families Delphinidae and Phocoenidae , and river dolphins .

虎鲸是最大也最具攻击性的海豚科动物

Orca - the largest and most predatory of the dolphin family .

不管海豚科动物多么聪明，相信它们具有救生的动机可能是错误的。

However intelligent they may be , it is probably a mistake to credit dolphins with any motive of lifesaving .

它们的牙齿较海豚科其他成员要少一些——通常其他成员有120颗，但巨头鲸只有40到48颗。

They also have fewer teeth than other members of the dolphin family - 40 to 48 as opposed to the usual 120 .

虽名虎鲸，但不同于海洋其他哺乳动物，非鲸目，海豚科的近亲。

Orcas are not related to whales at all , other than being ocean-dwelling mammals . Rather , they are close kin to dolphins .

虎鲸在海豚科动物中体型最大，体重重达6吨，体长长达32英尺。

Killer whales are the largest species of the dolphin family , and they can weigh up to six tons and grow to almost 32 feet long .

那么，把以上所举的理由归纳一下，我认为这个动物是属于脊椎动物门，哺乳动物纲，鱼类，鲸鱼目。它所属的科，是长须鲸、大头鲸、海豚的那一科；

Now , for all the reasons put forward to this point , I believed that this animal was a member of the branch Vertebrata , class Mammalia , group Pisciforma , and finally , order Cetacea .