(Hays, 1970; Axoprunum angelinum in Kling, 1973 and Foreman, 1975)
The top of the zone is defined by the morphotypic last appearance of Stylatractus universus and is coincident with the lower limit of the Botryostrobus aquilonaris Zone. This zone roughly corresponds to the Psi Zone in Antarctic sediments (Hays, 1965).
Events included in the zone are:
- Tm Lamprocyrtis neoheteroporos
- Tm Theocorythium vetulum may be coincident with the base of this zone.
The base of the zone is defined by the morphotypic last appearance of Eucyrtidium matuyamai and is coincident with the upper limit of the Eucyrtidium matuyamai Zone.Reference slides R 51.1, R 51.2 and R 51.3 from Sample 18-173-4-4, 46-50 cm.