Kozłowska, A., Bates, D., Zalasiewicz, J. and Radzevičius, S. 2019. Evolutionary significance of the retiolitine Gothograptus (Graptolithina) with four new species from the Silurian of the East European Platform (Baltica), Poland and Lithuania . Zootaxa. 4568, 3 (Mar. 2019), 435–469. DOI:https://doi.org/10.11646/zootaxa.4568.3.2.