Echinodermata

Trachelocrinida Sumrall, Sprinkle et Guensburg, 1997

Selection of related publications
Kõrts, A. 1989. Brachiolar plates of Bockia (Eocrinoidea) from the Middle Ordovician of Estonia and Leningrad Region. Fossil and Recent Echinoderm researches, pp. 34-37.
Bockelie, J. F. 1981. The Middle Ordovician of the Oslo Region, Norway: 30. The eocrinoid genera Cryptocrinites, Rhipidocystis and Bockia. Norsk Geologisk Tidsskrift 61, 2, 123-147.
Rõõmusoks, A. 1970. Stratigraphy of the Viruan Series (Middle Ordovician) in Northern Estonia, I.
Hecker, R. F. 1940. Nižnesilurijskie i devonskie iglokožie. Carpoidea, Eocrinoidea i Ophiocistia nižnego silura Leningradskoj oblasti i Èstonii . Transactions of the Paleontological Institute (PIN) 9, 4, 5-82.
Hecker, R. F. 1938. Novye dannye o rode Rhipidocystis Jkl (otrâd Digitata n. o., klass Carpoidea Jkl) i novyj rod Bockia (podklass Eocrinoidea Jkl, klass Crinoidea Mill.) iz nižnego silura Leningradskoj oblasti SSSR i Èstonii. Dokladõ Akademii nauk SSSR 19, 5, 421-425.