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The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period) and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out.
This list of trilobites is a comprehensive listing of all genera that have ever been included in the Arthropod class Trilobita, excluding purely vernacular terms.
Olenelloides armatus is an extinct, small sized (about 1 centimetre or 0.39 inches long) olenelloid redlichiid trilobite arthropod. It lived during the later part of the Botomian stage , [ 1 ] which lasted from approximately 524 to 518.5 million years ago.
Olenellus is an extinct genus of redlichiid trilobites, with species of average size (about 5 centimetres or 2.0 inches long). It lived during the Botomian and Toyonian stages ( Olenellus -zone), 522 to 510 million years ago , in what is currently North-America, part of the palaeocontinent Laurentia .
Asaphellus is an extinct genus of trilobites reported from the Ordovician. It is seen in Argentina, Bolivia, Mexico, America, Algeria, Iran, Spain, Portugal, France, Great Britain, Czech Republic, Norway, Sweden and China. [1] [2] [3]
Archaeaspis is an extinct genus of redlichiid trilobites. It lived during the late Atdabanian stage, [3] which lasted from 521 to 514 million years ago during the early part of the Cambrian Period. The first specimens were first found in Siberia, where they were originally thought to have been endemic.
Trinucleidae is a family of small to average size asaphid trilobites that first occurred at the start of the Ordovician and became extinct at the end of that period. It contains approximately 227 species divided over 51 genera in 5 subfamilies. [1] The most conspicuous character is the wide perforated fringe of the head.
Bristolia is an extinct genus of trilobite, fossil marine arthropods, with eight or more small to average size species. [1] It is common in and limited to the Lower Cambrian (Upper Olenellus -zone ) shelf deposits across the southwestern US, which constitutes part of the former paleocontinent of Laurentia .