奥陶纪 / 奧陶紀

ào​táo​jì

Ordovician period

The second geological period of the Paleozoic Era, occurring approximately 485 to 444 million years ago; characterized by limestone and shale deposits and the dominance of marine life like graptolites and trilobites

奥 (phonetic) 陶 (phonetic) 纪 (literal) → 纪/紀 · jì · era

Changed: simplified, traditional, gloss, definition, pinyin, variant pinyin, variants, separable parts, decomposition

created sense May 20, 2026, 07:57 PM