Permian period
Geological period name; used in academic and educational contexts. Cross-referenced with ペルム紀, which is the more common term.
See also: ペルム紀
The Permian period is the last period of the Paleozoic era.
A translation of Dyas, an older European geological name for the Permian based on its division into two major strata; 二畳 expresses this “twofold” structure.