This list of fossil arthropods described in 2018 is a list of new taxa of trilobites, fossil insects, crustaceans, arachnids, and other fossil arthropods of every kind that were described during the year 2018, as well as other significant discoveries, and events related to arthropod paleontology occurring in 2018.
General research A study on extant arthropods (mainly insects and spiders) living around the resinous tree Hymenaea verrucosa in the lowland coastal forest of Madagascar and trapped by the resin produced by this tree species, and on their implications for inferring whether amber records the true past biodiversity of the entire forest, is published by Solórzano Kraemer et al. (2018). A study on the early evolution of stem and crown-arthropods as indicated by Ediacaran and Cambrian body and trace fossils is published by Daley et al. (2018). A study on the evolution of ecdysozoan vision, focusing on the evolution of arthropod multi-opsin vision, as indicated by molecular data and data from fossil record, is published by Fleming et al. (2018). Grimaldi et al. (2018) report biological inclusions (fungi, plants, arachnids and insects) in amber from the Paleogene Chickaloon Formation of Alaska, representing the northernmost deposit of fossiliferous amber from the Cenozoic. A mantis lacewing larva found in association with two spiders, attached to one of the anterior walking legs of one of the spiders, is described from the Cretaceous amber from Myanmar by Haug, Müller & Haug (2018), who interpret this finding as evidence of palaeo-parasitism.
Arachnids
Research Review of arachnids known from the Bitterfeld amber (Germany) and a study on their implications for inferring the age of this deposit is published by Dunlop et al. (2018). The first fossil representative of the parasitic mite family Pterygosomatidae, assigned to the genus Pimeliaphilus and similar in morphology to the extant species parasitic on cockroaches, is described from the Cretaceous (Albian) Archingeay amber (France) by Sidorchuk & Khaustov (2018). Fossil mite "Sejus" bdelloides, originally interpret as a member of Mesostigmata, is reinterpreted as a member of Prostigmata referrable to the group Anystina by Dunlop, Walter & Kontschán (2018). A study on the body size of fossil mites is published by Sidorchuk (2018). A hard tick wrapped in spider silk is described from the Cretaceous Myanmar amber by Dunlop et al. (2018). A male specimen of a tick belonging to the genus Ornithodoros and the subgenus (Alectorobius) is described from the Dominican amber by Estrada-Peña & de la Fuente (2018), who also provide illustrated interpretations intended to support the validity of the identity of the fossils reported by de la Fuente (2003). A pseudoscorpion attached to barbules of a contour feather, possibly documenting a phoretic association between pseudoscorpions and Mesozoic birds, is described from the Cretaceous amber from Myanmar by Xing, McKellar & Gao (2018). A study on the phylogenetic history of spiders, based on molecular data and re-examination of the global fossil record, as well as on the ancestral predatory strategies among different groups of spiders and some of the possible drivers of spider diversification during the Early Cretaceous greenhouse, is published by Shao & Li (2018). A study on the burrows produced by wolf spiders belonging to the genus Pavocosa, aiming to identify ichnological signatures which may facilitate identification of wolf spider burrows in the fossil record, is published by Mendoza Belmontes, Melchor & Piacentini (2018). Fossil crevice weaver Misionella didicostae from Dominican amber is transferred to the genus Antilloides by Magalhaes (2018). Evidence of a fossilized cobweb, and a possible case of predation of a theridiid spider on a dolichopodid fly, are reported from the Mexican amber by García-Villafuerte (2018).
New taxa