有ゆう孔こう虫ちゅう

noun

foraminifer; foraminiferan

A type of single-celled marine organism with a perforated shell; used in biology and paleontology.

• 有ゆう孔こう虫ちゅうの化か石せきは地ち層そうの年ねん代だいを決きめるのに使