Type
Zone
Age range
205.7–202.2 Ma
Late Triassic
Rhaetian
Norian
Choristoceras crickmayi
Chochloceras amoenum
Gnomohalorites cordilleranus
205.8205.6205.4205.2205.0204.8204.6204.4204.2204.0203.8203.6203.4203.2203.0202.8202.6202.4202.2