英语语法分析

This species, also known as crinoids, is a highly mobile form of sea star.

同为海百合纲的海羽星是一种高度灵活的海星形式。

Before this extinction, Marine animals were mostly filter feeders stuck in place on the seafloor, such as crinoids or "sea lilies."

这次大灭绝之前，海洋动物大部分是固定在海底的滤食动物，比如海百合。

Like their sea star cousins, crinoids have five or more arms and askeleton constructed of calcified plates elaborately slotted together.

像海星一样，海百合也有五条或者更多条长腕，还有一个由钙化层整齐排列在一起的外壳。