Published online by Cambridge University Press: 12 November 2019
Three new Llandovery (early Silurian) crinoids from Estonia provide an improved understanding of the paleogeographic aspects of the crinoid diversification following the end-Ordovician extinctions. The new taxa are Euspirocrinus hintsae new species (Rhuddanian eucladid), Oepikicrinus perensae new genus new species (Aeronian camerate), and Rozhnovicrinus isakarae new genus new species (Aeronian eucladid). This brings the total of described Llandovery crinoids in Estonia to eight nominal species and a further three taxa in open nomenclature. The Rhuddanian radiation in Baltica mirrored that on Laurentia and Avalonia and was dominated by Ordovician clades that continued to diversify during the Silurian. Known Aeronian crinoids from Estonia continue these clades, whereas new clades diversified on Laurentia and Avalonia. However, by the Wenlock, a largely cosmopolitan fauna existed on Laurentia, Avalonia, and Baltica.