vestigial

例句：

1. 1. The fossils found in the cave are vestigial remnants of ancient life.
   洞穴中发现的化石是古代生命的残留痕迹。
2. 2. The species has vestigial features that make it difficult to tell it apart from other animals.
   这种物种具有难以辨认的特征，这使得它与其他动物很难区分开来。
3. 3. The dinosaurs had vestigial tails that were not as useful as their modern counterparts.
   恐龙们拥有不实用的尾巴，这在现代生物中并不常见。