Bryozoa

Helopora spiniformis (Ulrich, 1882)

Selection of related publications
Männil, R. M. 1959. Questions of stratigraphy and bryozoans of the Ordovician of Estonia.
Toots, H. 1952. Bryozoen des estnischen Kuckersits. Mitt. Geol. Staatinst. Hamburg 21, 113-137.
References based on distribution