Class

Hexactinellida Schmidt, 1870

glass sponges

Selection of related publications
Botting, J. P., Rhebergen, F. 2011. A remarkable new Middle Sandbian (Ordovician) hexactinellid sponge in Baltic erratics. Scripta Geologica 143, 1-14.
Rhebergen, F., von Hacht, U. von 2000. Ordovician erratic sponges from Gotland, Sweden. GFF 122, 4, 339-349. DOI:10.1080/11035890001224339
Jensen, S. 1997. Trace fossils from the Lower Cambrian Mickwitzia sandstone, south-central Sweden. Fossils and Strata 42, 1-110.
Lindström, M. 1979. Calcispongea from Ordovician Orthoceratite limestone of Sweden. GFF 101, 3, 237-239. DOI:10.1080/11035897909448579
Müürisepp, K. 1964. Käsnaläätsedest pakerordi lademes. Loodusuurijate Seltsi Aastaraamat, pp. 17-24.
Asatkin, B. P. 1949. Type Porifera. Sponges. pp. 63–73. Gosudarstvennoe Izdatel'stvo Geologicheskoj Literatury.
Öpik, A. 1930. Beiträge zur Kenntnis der Kukruse-(C2-C3-)Stufe in Eesti. IV. Tartu Ülikooli Geoloogia Instituudi Toimetused 24, 1-34.
List of species
1. Calcihexactina franconica Sdzuy, 1969 | CambrianOrdovician
3. Pyritonema subulare (Roemer, 1861) | Idavere SubstageJõhvi Substage