Geological period from . 270 to 220 million years ago.
The time period between 280-345 Myr BP of Earth's geologic history. Characterized by glacial onsets and melting and massive migration and extinctions of species during this period. [Geology;v18; 809-811;1990] [Geology;v17; 408-411;1989
a period 360 - 286 million years ago. It takes its name from the thick coal-producing carbon layers. This carbon was formed from the remains of swampy tropical forests that were flooded by shallow seas.