noun
trilobite
Extinct marine arthropod; used in scientific and educational contexts.
三葉虫は古生代に繁栄した節足動物です。
Trilobites are arthropods that flourished in the Paleozoic era.
From 三 (three) + 葉 (lobe) + 虫 (bug, insect), referring to the three-lobed body plan of trilobites.