First of all, they build shells that are unique to each species, with features like armoured plates, spines and sometimes even teeth.

首先，它们建造的外壳对每个物种来说都是独特的外壳形状，包括鳞甲 、脊椎，有时甚至是牙齿。

The fossil is spectacularly preserved, which let the team study its armoured plates in detail.

化石保存完好，这让团队可以详细研究它的装甲板。