(Sanfilippo and Riedel in Saunders et al., 1985)
The top of the zone is defined by the mophotypic last appearance of Thyrsocyrtis tetracantha and is coincident with the lower limit of the Cryptocarpium ornatum Zone.
Events included in this zone are:
- Tm Thyrsocyrtis triacantha
- Bm Theocyrtis tuberosa
- Tm Eusyringium fistuligerum
- Tm Podocyrtis goetheana
The base of the zone is defined by the morphotypic first appearance of Calocyclas bandyca and is coincident with the upper limit of the Cryptocarpium azyx Zone.
Reference slides R 37.1, R 37.2 and R 37.3 from Sample 17-167-28-4, 107-112 cm.