of Marrella splendens from the Burgess Shale, originally interpreted as evidence that the animal's blood contained the Cu-bearing protein hemocyanin, is published by Gaines et al. (2019). A study on the anatomy of the nervous system of Alalcomenaeus is published by Ortega-Hernández, Lerosey-Aubril & Pates (2019). Juvenile specimens of stylonurine eurypterids belonging to the family Hardieopteridae are described from the Famennian locality of Strud (Belgium) by Lamsdell et al. (2019), who interpret their findings as evidence indicating that eurypterids underwent a marine to freshwater transition during the Devonian, and that juvenile eurypterids inhabited sheltered nursery pools (and migrated to rivers upon reaching maturity). A study on the structure of the eyes of eurypterids is published by Schoenemann, Poschmann & Clarkson (2019). A study on ontogenetic changes in prosomal morphology in Carboniferous horseshoe crab Euproops danae is published by Tashman, Feldmann & Schweitzer (2019). A study on the anatomy of the appendages of the Cretaceous xiphosurid Tachypleus syriacus and on the evolution of fossil horseshoe crab appendages is published by Bicknell et al. (2019). A study re-evaluating the fossil evidence for lateral compound eyes in Paleozoic horseshoe crabs is published by Bicknell, Amati & Ortega-Hernández (2019). A study on the morphology of the millipede Phryssonotus burmiticus'' from the Cretaceous amber from Myanmar is published by Su, Cai & Huang (2019). New taxa References 2019 in paleontology