old fossils.

• 古代的化石

old fossils.的用法和样例：

例句

1. Potential fossils are relatively rare in the final deposits of normal quartz-sand beaches.
   在正常的石英质海滩的最终沉积物中隐匿的化石还是比较少的。
2. Since then, however, many more fossils documenting this transformation have come to light.
   然而，在那之后，人们找到了更多记录了蜕变过程的化石。