The boundary between the Rakvere and Nabala RSs is biostratigraphically easy to recognize by the presence of the chitinozoan
zonal species Armoricochitina reticulifera (Grahn) in the lowermost Montu or Paekna Fms (Mannil & Meidla 1994; Nolvak et al.
Precise time-correlation in the Ordovician can be achieved by biostratigraphical methods, particularly using graptolite, conodont and chitinozoan
In the chitinozoan
biozonation, the Eisenackitina rhenana Subzone of the Laufeldochitina stentor Zone corresponds to the lower part of the Kukruse Stage (Nolvak & Grahn 1993; Nolvak 1997).
A multiproxy study of the Katian and Hirnantian in the Puhmu core in NE Estonia resulted in new data on chitinozoan
and brachiopod biostratigraphy.
Upper Llandovery to Middle Wenlock (Silurian) lithostratigraphy and chitinozoan
biostratigraphy in southwestern Estonia and northernmost Latvia.
dynamics and biostratigraphy in the Vao Formation
fauna recovered from the GSSP section and a supplementary limestone section in Oklahoma supports correlation with the Baltic Spinachitina cervicornis Zone (Goldman et al.
Those of seven chitinozoan
biozones are presented according to Nestor (2009, 2011, 2012), seven conodont ones from Viira & Aldridge (1998) and Viira (1999, 2000) and seven vertebrate indices according to Marss (1986, 1997) and Marss & Mannik (2013).
The boundary is succeeded by chitinozoan
Interzone IV (Nestor 1994) and the Conochitina mamilla and Conochitina tuba zones.
savalaensis from the East Baltic, however, exhibit a limited temporal range, being restricted to the lower part of the Eisenackitina rhenana Subzone within the Laufeldochitina stentor chitinozoan
Zone (Nolvak & Grahn 1993; Nolvak et al.
biozonation and data on bentonite beds are employed in the correlation of the sections and the analysis of facies shifts caused by sea-level rises and falls.