|M. aliena from Vokovice, Prague (Czech Republic)|
|Genus:||† Megistaspis |
Megistaspis is a genus of trilobites in the order Asaphida and family Asaphidae .
They lived in the Ordovician period (478-449 million years ago),from the Upper Tremadocian age until the Lower Llanvim age. These arthropods were a low-level epifauna, fast-moving and detritivore.
Ordovician of Australia, China, Colombia (Serranía de la Macarena, Meta), the Czech Republic, Iran, Norway, United States (Nevada); Arenig of Argentina, Bolivia, China, France, Norway, Sweden, United States (Montana); Dawan of China; Arenigian of Argentina.
Dolerorthis is an extinct genus of hesperorthid brachiopod. The type species of this genus, D. interplicata, was described from the Silurian (Telychian) Osgood Formation. Other species belonging to this genus are known from the Ordovician and Silurian of Europe, Kazakhstan, China and Argentina. It was roughly 4 centimetres (1.6 in) across.
Hoekaspis is an extinct genus of trilobites from the family Asaphidae. It lived during the early part of the Arenig stage of the Ordovician, a faunal stage which lasted from approximately 466 to 461 million years ago.
Pytine is an extinct genus of asaphid trilobites. Species lived during the later part of the Arenig stage of the Ordovician Period, approximately 478 to 471 million years ago. Various species are found in the Svalbard, Valhallfonna Formation, Olenidsletta, Member, of Spitzbergen, Norway, the Megistaspis (Paramegistaspis) planilimbata Zone of the 'Shumardia Shale' of Sweden, Jujuy Province, Argentina, early Arenig-aged strata of Jiangxi province, China, and Darriwilian-aged strata in Western Hunan province, China. The type species, P. graia, has seven thorax segments, and lacks the rapier-like glabellar spine, that occurs in many other raphiophorids. The Chinese species, by contrast, have only six thoracic segments. So far, only the type species, and one of the Chinese species, P. laevigata, are known from complete specimens.
Dipleura is a genus of trilobites in the order Phacopida. It was described by Green in 1832, and the type species is Dipleura dekayi. The type locality was in the Hamilton Group in New York.
Kionoceras is an extinct nautiloid cephalopod genus included in the orthocerid family Kionoceratidae with scattered worldwide distribution from the Middle Ordovician to the Lower Permian. Kionoceratids are orthocerids with prominent longitudinal ornamentation on their shells, sometimes augmented by secondary transverse ornamentation. Orthocerids are, of course, prehistoric nautiloides with generally straight and elongate shells, mostly with central or subcentral siphuncles.
Hoeloceras is an extinct orthoconic nautiloid cephalopod from the upper Ordovician, generally included in the Actinocerida. Nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a couple of genera, Nautilus and Allonautilus.
Paradnatoceras is an extinct straight-shelled cephalopod genus that lived in what would become China during the Ordovician from 478.6 to about 461 mya, existing for approximately 17.6 Ma.
Didymograptus is an extinct genus of graptolites with four rows of cups. They lived during the Middle Ordovician, to Late Ordovician.
Tetragraptus is an extinct genus of graptolites from the Ordovician period.
Dichograptus is an extinct genus of graptolites from the Ordovician.
Bumastus is an extinct genus of corynexochid trilobites which existed from the Early Ordovician period to the Late Silurian period. They were relatively large trilobites, reaching a length of 6 in (15 cm). They were distinctive for their highly globular, smooth-surfaced exoskeleton. They possessed well-developed, large compound eyes and were believed to have dwelled in shallow-water sediments in life.
Birmanites is a genus of trilobites in the order Asaphida, family Asaphidae.
Strophomena is a genus of brachiopods belonging to the order Strophomenida family Strophomenidae, named by Rafinesque in 1824. They were stationary epifaunal suspension feeders.
Holopea is an extinct genus of fossil sea snails, Paleozoic gastropod mollusks in the family Holopeidae.
Gangshanoceras is a fossil nautiloid cephalopod genus included in the orthocerid family Proteoceratidae. It has been found in Ordovician rocks dated from about 478.5 to 468 Ma in China, and from rocks dated slightly younger, about 468 to 461 Ma in Argentina. It has five described species. The type is Gangshanoceras jurongense.
Geragnostus is a genus of very small agnostid trilobites whose fossils are found Ordovician-aged marine strata from Eurasia, North America and Argentina.
Amplexopora is a genus of bryozoans known in the rock record from the Ordovician to the Permian periods. Species belonging to this genus were stationary epifaunal suspension feeders.
Phyllopachyceras is an extinct genus of ammonoid cephalopods belonging to the family Phylloceratidae. These nektonic carnivores lived in the Cretaceous, from Hauterivian to Maastrichtian to age.
Utahconus is an extinct genus of conodonts.
Cordylodus is an extinct genus of conodonts in the family of Cordylodontidae.