(Riedel and Sanfilippo, 1970, emend. 1978a)
The top of the zone is defined by the morphotypic first appearance of Eusyringium lagena and is coincident with the lower limit of the Thyrsocyrtis triacantha Zone.
Events included in the zone are:
- Tm Lamptonium fabaeforme fabaeforme; Bm Podocyrtis dorus
- Theocotyle cryptocephala -> Theocotyle conica
- The lower limit of the zone is approximately synchronous with Tm Calocycloma castum
The base of the zone is defined by the morphotypic first appearance of Dictyoprora mongolfieri and is coincident with the upper limit of the Theocotyle cryptocephala Zone.
Reference slides R 44.1, R 44.2 and R 44.3 from Sample 10-94-22-3, 44-52 cm.