Triassic (adj.)youdaoicibaDictYouDict[Triassic 词源字典]
1841, from German, coined 1841 by German geologist Friedrich August von Alberti (1795-1878), from Trias "period preceding the Jurassic," from Greek trias "triad, the number three" (see triad). So called because it is divisible (in Germany) into three groups.[Triassic etymology, Triassic origin, 英语词源]