Index fossil
01
示準化石, 指標化石
a fossilized organism that is useful for dating and correlating the strata in which it is found, typically indicative of a particular time period in Earth's geological history
例
The trilobite is an index fossil commonly used to date Paleozoic rock layers.
三葉虫は、古生代の岩層を年代測定するために一般的に使用される示準化石です。
