graptolite
An extinct marine invertebrate from the Paleozoic era; a technical term in paleontology.
フデイシは古生代の示準化石として重要だ。
Graptolites are important as index fossils of the Paleozoic era.
この
Many graptolite fossils were found in this stratum.
Katakana spelling is standard for this scientific term.
Kanji spelling is rare; the word is usually written in kana.
From 筆 (fude, 'brush') + 石 (ishi, 'stone'), referring to the brush-like appearance of the fossil.