由于恐龙谷缺水,导致大恐龙们反目成仇,“小足”和它四位朋友为此展开寻水之旅。一路上,小恐龙们历经暴龙的攻击,但它们仍勇往直前,成功地将遭受陨石阻塞的水源通顺,由于小恐龙的无私及勇气令大恐龙了解到共施共享的价值,而“小足”及伙伴们因此经验也学到了同心协力的意义。A nearby meteorite crash blocks off the dinosaurs' water supply, starting an ecological chain-reaction that threatens life in the valley. All the dinosaurs, including a group of stupid bullies, must cooperate in an effort to free the blockage, which involves a risky venture outside the valley.