Xiphosurus polyphemus

large marine arthropod of the Atlantic coast of North America having a domed carapace that is shaped like a horseshoe and a stiff pointed tail; a living fossil related to the wood louse

馬蹄形のドーム状背甲と硬く尖った尾を持つ北米大西洋沿岸の大型海洋節足動物；ワラジムシに近縁な生きた化石