Silurian | | | A member of Myodocopa belonging to the superfamily Bolbozoidea. The type species is "Entomis" depressa Jones (1884). | |- |Tenedocythere? rugosocostata| Sp. nov | Valid | Nogueira, Ramos & Hunt | Early Miocene | Pirabas Formation | | A member of Podocopida belonging to the family Hemicytheridae. | |- |Touroconcha ishizakii| Sp. nov | Valid | Nogueira, Ramos & Hunt | Early Miocene | Pirabas Formation | | A member of Podocopida belonging to the family Loxoconchidae. | |- |Uthoernia sibirica| Sp. nov | Valid | Melnikova | Late Ordovician | Delingde Formation | | | |- |} Other crustaceans Insects Trilobites Research A study on the rates of evolution of trilobites in the Cambrian is published by Paterson, Edgecombe & Lee (2019), who interpret their findings as indicative of Cambrian rather than Precambrian origin of trilobites, and as indicating that the Cambrian explosion had already largely concluded by the time the typical Cambrian fossil record begins (≈521 Ma). A study on repaired injuries in trilobite specimens from the Cambrian Ruin Wash Lagerstätte (Nevada, United States) is published by Pates & Bicknell (2019), who interpret their findings as indicative of species specific predation on Cambrian trilobites, and of enlarged spines in some trilobite species serving as possible predation deterrents. A study on the morphology and ontogeny of Changaspis elongata, based on data from specimens from the Lazizhai section of the Balang Formation (Cambrian Stage 4; Guizhou, China), is published by Du et al. (2019). A cluster of over a 100 juvenile trilobites belonging to the genus Aphelaspis is reported from the Cambrian (Paibian) Conasauga Formation (Georgia, United States) by Schwimmer & Montante (2019). A study on patterns of occupancy and diversity trajectories in late Cambrian-early Ordovician trilobite communities from the Argentine Cordillera Oriental is published by Serra, Balseiro & Waisfeld (2019). A study on the phylogenetic relationships of members of the family Olenidae is published by Monti & Confalonieri (2019). A study on the phylogenetic relationships of members of the olenid subfamily Balnibarbiinae is published by Hopkins (2019). Nine specimens of Symphysurus ebbestadi preserving all key stages of the exoskeleton moulting process are described from the Lower Ordovician Fezouata Formation (Morocco) by Drage et al. (2019). A study on clusters of Ampyx priscus from the Ordovician Fezouata Shale of Morocco is published by Vannier et al. (2019), who interpret these clusters as evidence of a collective