This list of fossil arthropods described in 2019 is a list of new taxa of trilobites, fossil insects, crustaceans, arachnids and other fossil arthropods of every kind that are scheduled to be described during the year 2019, as well as other significant discoveries and events related to arthropod paleontology that are scheduled to occur in the year 2019. General research A revision of higher-level arthropod taxonomy is published by Aria (2019), who proposes the name Cenocondyla for the least inclusive group containing both Mandibulata and Chelicerata. A study on the molecular composition and microanatomy of the eyes of 54-million-year-old crane flies from the Fur Formation (Denmark), evaluating its implications for the knowledge of optical systems of other ancient arthropods (especially trilobites), is published by Lindgren et al. (2019). Arachnids Research Two new specimens of laniatorid harvestmen (an adult specimen assignable to the species Proholoscotolemon nemastomoides and a smaller specimen belonging or related to the genus Proholoscotolemon) are described from the Eocene Baltic amber by Bartel & Dunlop (2019). A review of the phylogenetic hypotheses of scorpion interrelationships, as well as of scorpion palaeontology, is published by Howard et al. (2019), who also provide a list of scorpion fossil calibrations for use in molecular dating. A fossil spider, possibly a juvenile female golden silk orb-weaver, is described from the Lower Eocene Palana Formation of the Gurha opencast lignite mine (western Rajasthan, India) by Patel, Rana & Selden (2019), representing the first fossil spider from India which wasn't found in amber. A review of the fossil record and evolutionary history of spiders, reevaluating the phylogenetic placement of key fossils and aiming to determine whether there has been a major turnover in the spider fauna between the Mesozoic and Cenozoic, is published online by Magalhaes et al. (2019). New taxa Crustaceans Research A global dataset of exceptionally preserved muscles and muscle attachment scars in fossil malacostracan specimens is compiled by Klompmaker et al. (2019). A three-dimensionally preserved tanaidacean specimen belonging or related to the species Jurapseudes friedericianus is described from the Middle Jurassic (Callovian) Ornatenton Formation (Germany) by Schädel et al. (2019). A study on the evolutionary history of decapod crustaceans is published by Wolfe et al. (2019). A study on the chemical composition of two specimens of fossilized shrimps from the Cretaceous Romualdo and Ipubi formations (Araripe Basin, Brazil), and on its implications for inferring the course of the processes of fossilization