Fig. 4 in Taxonomy and ontogeny of the Lituitida (Cephalopoda) from Orthoceratite Limestone erratics (Middle Ordovician)

Fig. 4. Stratigraphic distribution of lituitid taxa in Ordovician strata of Baltoscandia and Ordovician erratics; black circles indicate unambiguous presence, grey circles indicate possible presence. Species with unknown stratigraphic occurrence are excluded from the scheme. Stratigraphic chart after Ebbestad & Högström (2007) and Meidla et al. (2014); stage slices after Bergström et al. (2009).