(Riedel and Sanfilippo, 1970, emend. 1978a)
The top of the zone is defined by the evolutionary transition from Podocyrtis phyxis to Podocyrtis ampla and is coincident with the lower limit of the Podocyrtis ampla Zone.
Events included in the zone are:
- Tm Theocotyle nigriniae; Tm Theocotyle conica; Podocyrtis diamesa -> Podocyrtis phyxis; Tm Theocorys anaclasta; Tm Lamptonium fabaeforme constrictum; Tm Lamptonium fabaeforme chaunothorax; Tm Thyrsocyrtis hirsuta; Tm Thyrsocyrtis robusta
- The lower limit of the zone is approximately synchronous with Thyrsocyrtis tensa -> Thyrsocyrtis triacantha
The base of the zone is defined by the morphotypic first appearance of Eusyringium lagena and is coincident with the upper limit of the Dictyoprora mongolfieri Zone.
Reference slides R 43.1, R 43.2 and R 43.3 from Sample 10-94-20-2, 70-77 cm.