Trilobites

Source: Wikipedia. Pages: 63. Chapters: Trilobite, Agnostida, Naraoiidae, Redlichiida, List of trilobites, Walcott-Rust quarry, Beecher's Trilobite Bed, Ptychopariidae, Olenoides, Elrathia, Asaphida, Trilobite zone, Naraoia, Olenellus, Proetida, Phacopida, Kootenia, Triarthrus, Odontopleurida, Solenopleuridae, Olenellina, Ptychagnostus, Redlichiina, Dolichometopidae, Lichida, Paradoxides, Zacanthoides, Dicranurus, Redlichia, Emuellidae, Harpetida, Corynexochida, Nektaspida, Bathyuriscus, Ceratarges, Acanthopyge, Chancia, Redlichiidae, Arctinurus, Nephrolenellus, Aulacopleura, Ogygopsis, Ellipsocephalus, Kleptothule, Nevadia, Oryctocephalus, Misszhouia, Acidaspis, Leonaspis, Terataspis, Paradoxides davidis, Fallotaspis, Paradoxididae, Ejinaspis, Kolihapeltis, Asaphiscus, Sinijanella, Poliellina, Poliellaspis, Mesonacis, Protolloydolithus, Estaingia bilobata, Redlichia takooensis, Emuella, Paralejurus, Corynexochina, Pagetia, Balcoracania dailyi, Emuella polymera, Changaspis, Eoredlichia, Selenopeltis, Alokistocaridae, Harpides, Thysanopeltis, Holmiidae, Morocconites, Szechuanella, Ehmaniella, Ogyginus, Xystridura, Phacopoidea, Liwiidae, Diaphanometopus, Hanburia, Strenuaeva, Liwia. Excerpt: This list of trilobites is a comprehensive listing of all genera that have ever been included in the class Trilobita, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (), or were not formally published (), as well as junior synonyms of more established names, and genera that are no longer considered trilobites. Naming conventions and terminology follow the International Code of Zoological Nomenclature. Technical terms used include: Bailiella levyi Boedaspis ensifer Ceratarges Uncited genera names can be attributed to Sepkoski (2002) and Jell & Adrain (2003). Trilobites ( , ; meaning "three lobes") are a well-known fossil group of extinct marine arthropods that form the class Trilobita. 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 era before beginning a drawn-out decline to extinction when, during the Devonian, all trilobite orders, with the sole exception of Proetida, died out. Trilobites finally disappeared in the mass extinction at the end of the Permian about . The trilobites were among the most successful of all early animals, roaming the oceans for over 270 million years. When trilobites first appeared in the fossil record they were already highly diverse and geographically dispersed. Because trilobites had wide diversity and an easily fossilized exoskeleton an extensive fossil record was left, with some 17,000 known species spanning Paleozoic time. The study of these fossils has facilitated important contributions to biostratigraphy, paleontology, evolutionary biology and plate tectonics. Trilobites are often placed within the arthropod subphylum Schizoramia within the superclass Arachnomorpha (equivalent to the Arachnata), although several alternative taxonomies are found in the literature. Trilobites had many life styles; some mo