1.After each extinction, a rich variety of ammonoid species and body plans was replaced by a few free-floating types.
在每次物种灭绝之中，大量的菊石和体平面为少量浮游动物所替代。
2.After each extinction, a rich variety of ammonoid species and body plans was replaced by a few free-floating types.
在每次物种灭绝之中，大量的菊石和体平面为少量浮游动物所替代。