The "messaoudensis-trifidum" acritarch assemblage (Ordovician: Tremadoc-Early Arenigian) from the subsurface of Rugen (Baltic Sea, northeast Germany).
Reference:
Servais,T. et al. (1997)
The "messaoudensis-trifidum" acritarch assemblage (Ordovician: Tremadoc-Early Arenigian) from the subsurface of Rugen (Baltic Sea, northeast Germany). Palaeontographia Italica
Vol. 84 P. 113- 161