280 Mya to 260 Mya

272.95 Mya, Permian, Guadalupian, Radian: Pelycosaurs, and therapsids, Synapsid reptiles, become plentiful 

268.8 Mya, Permian, Guadalupian, Wordian: End of glaciation? Synapsid reptiles (pelycosaurs and therapsids)are plentiful while parareptiles and temnospondyl amphibians remain common.

265.1 Mya, Guadalupian, Capitanian: End of Permo Carboniferous glaciation,