Echinodermata

Ristnacrinus Öpik, 1934

Selection of related publications
Ausich, W. I., Rozhnov, S. V. & Kammer, T. W. 2015. Iocrinid Crinoids from the Ordovician of the Baltic Region, Estonia. Paleontological Journal 49, 2, 145-152. DOI:10.1134/S0031030115020069
Stukalina, G. A. 1986. Laws of historical development of crinoidea in the early and middle Paleozoic of the USSR.
Donovan, S. K. 1984. Ristnacrinus and the earliest myelodactylid from the Ashgillian Boda Limestone of Sweden. GFF 109, 4, 347-356. DOI:10.1080/11035898509454663
Yakovlev, N. N. 1956. A revision of the characteristics of the genus Ristnacrinus Öpik. Yearbook of All-Union Paleontological Society XV, 155-157.
Öpik, A. 1934. Ristnacrinus, a new Ordovician crinoid from Estonia. Tartu Ülikooli Geoloogia Instituudi Toimetused , 40, 1-7.