This monograph is a summary of the conference on Eurytemora, gathering renowned researchers from all over the world to discuss new advances in Phylogeny, Biogeography, Taxonomy, and Ecology of this important group of estuarine crustaceans, held the 13-17 May 2019 in St. Petersburg, Russia. The present volume includes 17 selected papers, in which you will discover new aspects of the modern theory on the history and recent geographical distribution (biogeography) of an important group of estuarine crustaceans, revealing coincidences with a modern model of continental drift. The researchers suggest a new hypothesis on time and place of origin of continental calanoid copepods. The specialists show that studying external morphology in detail helps to increase identification and differentiation between closely related sibling species within the Eurytemora group. Several ecological questions on invasive and pseudocryptic copepod species are debated. Finally, the last chapter of this monography is devoted to taxa related to the Eurytemora group, Epischura, Temora, Temoropia, and Pseudodiaptomus. First published as a Special Issue of Crustaceana 93(3-5): 241-547.