Asaphida is a large, morphologically diverse order of trilobites found in marine strata dated from the Middle Cambrian until their extinction during the Silurian. Asaphida contains six superfamilies, but no suborders. Asaphids comprise some 20% of described fossil trilobites.
Protaspididae is an extinct family of pteraspidid heterostracan agnathans. Fossils of the various genera are found in early Devonian-aged marine strata. Protaspidids were once thought to represent a transitional form between the Pteraspididae and the Psammosteida, bearing the broad head shield shape of the latter, due to a more benthic (bottom-dwelling) existence, but recent phylogenical comparisons demonstrate that the protaspidids are actually highly derived pteraspidids, and that the anchipteraspidids, the most primitive of pteraspidids, are the sister-group of the Psammosteids.
Redlichia is a genus of redlichiid trilobite in the family Redlichiidae, with large to very large species. Fossils of various species are found in Lower Cambrian (Toyonian)-aged marine strata from China, Korea, Pakistan, the Himalayas, Iran, Spain, southern Siberia, and Antarctica, and from Middle Cambrian (Ordian)-aged marine strata of Australia.
Bolbocephalus is a genus of proetid trilobites in the family Bathyuridae. Species lived during the early part of the Arenig stage of the Ordovician Period, a faunal stage which lasted from approximately 478 to 471 million years ago, in marine strata of the United States, Canada, and Greenland.
Hypodicranotus striatulus is an extinct, pelagic trilobite in the order Asaphida, of the family Remopleuridae. Its fossils are found in Middle Ordovician-aged marine strata in New York State, United States, and in Ontario, Canada.
Endops yanagisawai is a proetid trilobite belonging to the family Proetidae, endemic to Middle Permian-aged marine strata in Fukushima Prefecture, Japan. It was originally described by Riuji Endo as Paladin yanagisawai.
Odontopleurida is an order of very spinose trilobites closely related to the trilobites of the order Lichida. Some experts group the Odontopleurid families, Odontopleuridae and Damesellidae, within Lichida. Odontopleurids tend to have convex, bar-shaped cephalons, and lobed, knob-shaped glabella that extend to, or almost to the anterior margin. Many, if not almost all odontopleurids have long spines that are derived either from the margins of the exoskeleton, or from granular or tubercular ornamentation, or both. Many odontopleurids are so spinose so as to be described as having "spines on (their) spines." Odontopleurids have 8 to 13 thoracic segments, with Odontopleuridae odontopleurids having no more than 10, and Damesellidae odontopleurids having no more than 13. The pygidium tends to be very small, and invariably has long spines emanating from it in all known genera.
Odontopleuridae is a family of odontopleurid trilobites found in marine strata throughout the world. Odontopleurids of Odontopleuridae first appear in Late Cambrian-aged marine strata, and the last genera perish by the end of the Frasnian stage during the Late Devonian. The members of Odontopleuridae are famous for their spinose appearance, having long, often numerous spines along the edges of their exoskeletons, and derived from ends of segments or tubercle ornaments.
Arcticalymene is a genus of trilobites found in Silurian-aged marine strata of Arctic Canada and Central Victoria, Australia. The Canadian species are named after each of the Sex Pistols: A. cooki, A. jonesi, A. matlocki, A. rotteni and A. viciousi, all named by Adrian and Edgecombe in 1997.
Proetus is a genus of proetid trilobite found in Silurian-aged marine strata of Europe.
Styginidae is a family of trilobite in the order Corynexochida. Fossils of the various genera are found in marine strata throughout the world, aged from Ordovician up until the family's extinction during the Silurian.
Entomaspididae is a family of harpetid trilobites that ranges from the Upper Cambrian to Lower Ordovician of marine strata in China and the United States.
Entomaspis is an extinct genus of harpetid trilobite from Upper Cambrian to Early Ordovician marine strata of the United States. Species are typified by their proportionally large, vaulted, croissant-shaped or bonnet-shaped cephalons that have the cheeks freed to become elongated, curved librigenial spines, and by their comparatively large, crescent-shaped eyes.
Triroetus is a genus of proetid trilobite found in Upper Carboniferous-aged marine strata in Russia, and Lower Permian-aged strata of Thailand, Malaysia, Spitzbergen, Yukon Territory, and Middle Permian-aged marine strata of Oman and Texas.
Nipponaspis is a genus of proetid trilobite belonging to the family Phillipsiidae. Fossils of the various species are found in Middle Permian-aged marine strata of Fukushima Prefecture, Japan, China, Korea, and Alaska.
Vidria vespa is a proetid trilobite belonging to the family Phillipsiidae. The fossils are found in Middle Permian-aged marine strata of Western Texas. It is unique among Permian-aged trilobites in having a posterior spine emanating from the pygidium of the adult.
Lichas is a genus of lichid trilobites from late Ordovician-aged marine strata of Europe and Morocco.
Persia praecox is a species of phillipsiid proetid trilobite from Tournaisian-aged marine strata in what is now Eastern Iran.
Malchi magnificus is a proetid trilobite belonging to the family Phillipsiidae. The exquisitely preserved fossils are found in Lower Carboniferous-aged marine strata of what is now Malchi Creek, Queensland, Australia.
Odontopleura is a genus of spinose odontopleurid trilobite in the family Odontopleuridae, and is the type genus of that family and of Odontopleurida. The various species are found in Upper Ordovician to Middle Devonian marine strata throughout the world. The best studied fossils are of the type species, O. ovata, from the Wenlock-aged Liteň Formation in Loděnice, in Bohemia, Czech Republic, and, southeastern Gotland, of Sweden.
