The top of the zone is defined by the evolutionary transition from Podocyrtis sinuosa to Podocyrtis mitra and is coincident with the lower limit of the Podocyrtis mitra Zone.
Events included in the zone are:
- Eusyringium lagena -> Eusyringium fistuligerum
- Bm Podocyrtis fasciolata; Bm Podocyrtis helenae
- The lower limit of the zone is approximately synchronous with Tm Theocotyle venezuelensis
The base of the zone is defined by the evolutionary transition from Podocyrtis phyxis to Podocyrtis ampla and is coincident with the upper limit of the Thyrsocyrtis triacantha Zone.
Reference slides R 42.1, R 42.2 and R 42.3 from Sample 10-94-18-4, 109-117 cm.