large extinct scorpion-like arthropod considered related to horseshoe crabs
例句
"eurypterid:any of various large, segmented aquatic arthropods of the order Eurypterida that existed from the Ordovician Period to the Permian Period." "(古生)板足鲎目的:一种巨大的、有节的;属于板足鲎目的水生节肢动物;生存于奥陶纪到二叠纪时期.;"