Like the three-meter-long Anthracosaurus... 比如三米长的石炭鲵

186. But it was already too late
     但对于这些叶鳍鱼来说
187. for these lobe-finned fish.
     已经太晚了
188. Others had made this transition before them.
     其他动物先它们一步完成了这种转变
189. Like the three-meter-long Anthracosaurus...
     比如三米长的石炭鲵
190. ...that had already found its feet.
     已经长出腿来
191. The evolution from fin to limb took millions of years.
     从鳍到肢的进化用了数百万年
192. But once completed,
     但一旦完成

来自《我们星球上的生命 第一季 第三集 Life on Our Planet S01E03 入侵大地》第 189 行