Embrik Strand, who helped confirm that Carcinosoma was not preoccupied. Strand would subsequently propose the replacement name Eusarcana in 1942, despite the problem having been dealt with by Størmer, who he had been in contact with eight years earlier. The reasons for proposing the name during the circumstances of the time remains unknown, but contemporary researchers critiquing Strand for his studies in systematics and an apparent desire to name as many taxa as possible may explain the situation somewhat. As it was seen as completely unnecessary at the time, Strand's Eusarcana was overlooked and not even mentioned in subsequent eurypterid studies. The naming of Eusarcana was one of many contributions to nomenclature by Strand seen as unhelpful today. His journal Folia Zoologica et Hydrobiologica would later re-emerge within the field to create all kinds of systematic problems that could have been avoided. Strand was also notorious for applying new species names to incomplete or poorly preserved fossils. In 1964, American paleontologists Kenneth Edward Caster and Erik N. Kjellesvig-Waering recognized Eusarcus and Carcinosoma to be distinct genera when revising the superfamily Carcinosomatoidea, and coined the replacement name Paracarcinosoma to designate the species previously assigned to Eusarcus. E. scorpionis was designated the type species. Caster and Kjellesvig-Waering made no mention of Embrik Strand or Eusarcana, and they were likely not aware of the existence of the previous name. With Eusarcana all but forgotten, all subsequent researchers used Paracarcinosoma for the genus. In 2012, American paleontologists Jason A. Dunlop and James Lamsdell noted that whilst the name Eusarcana had been completely unnecessary (and of questionable validity, as Strand did not designate a type species) at the time of its creation, it is the oldest available valid name for the taxon and as such should constitute its name under the rules of priority, despite Paracarcinosoma being more widely used. As such, Paracarcinosoma was designated as a junior synonym, with all three species assigned to it being transferred to Eusarcana. Classification Eusarcana is classified as part of the family Carcinosomatidae, a family within the superfamily Carcinosomatoidea, alongside the genera Carcinosoma, Eocarcinosoma, Rhinocarcinosoma and possibly Holmipterus. The cladogram below is adapted from a larger cladogram (simplified to only display the Carcinosomatoidea) in a 2007 study by eurypterid researcher O. Erik Tetlie, in turn based on results from various phylogenetic analyses on eurypterids conducted between 2004 and 2007. The second cladogram below is simplified from a study