until they are big enough to join the rest of the herd. 直到它们长大到足以加入龙群

186. At last, she reaches her own nest.
     最后 它到达了自己的巢穴
187. She feeds her young in a very bird-like way.
     它以一种与鸟类非常相似的方式 喂养幼龙
188. She'll protect them in the nest for many months,
     它会在巢穴中保护它们达数月之久
189. until they are big enough to join the rest of the herd.
     直到它们长大到足以加入龙群
190. Yet the planet didn't just support large numbers of dinosaurs,
     然而 地球不仅支撑了大量的恐龙
191. its stability also supported dinosaurs of every shape and size.
     地球的稳定 也支撑了各种形状和大小的恐龙
192. Triceratops is very different to the defenseless Maiasaura.
     三角龙 与无防御能力的慈母龙非常不同

来自《我们星球上的生命 第一季 第一集 Life on Our Planet S01E01 生命法则》第 189 行