Ptychopariida genera

thumb|right|250px|Elrathia kingii growth series with holaspids ranging from 16.2 mm to 39.8 mm in length

Triarthrus is a genus of Upper Ordovician ptychopariid trilobite found in New York, Ohio, Kentucky, and Indiana, eastern and northern Canada, China and Scandinavia. It is the last of the Olenid trilobites, a group which flourished in the Cambrian period. The specimens of T. eatoni that are found in the Beecher's Trilobite Bed, Rome, New York area are exquisitely preserved showing soft body parts in iron pyrite. Pyrite preservation has given scientists a rare opportunity to examine the gills, walking legs, antennae, digestive systems, and eggs of trilobites, which are rarely preserved. Triarthr

Ellipsocephalus Zenker, 1833, is a genus of blind Cambrian trilobite, comprising benthic species inhabiting deep, poorly lit or aphotic habitats. E. hoffi is a common trilobite mainly from central Europe (Czech Republic).

Asaphiscus is a genus of trilobite that lived in the Cambrian. Its remains have been found in Australia and North America, especially in Utah.

Yunnanocephalus is a genus of ptychopariid trilobite. It lived during the late Atdabanian and Botomian stages, in what are currently Antarctica, Australia and China. It was a "moderately common" member of the Chengjiang Fauna.

fossil genus of trilobites

Conocoryphe is a genus of primarily eyeless trilobites belonging to the family Conocoryphidae. They lived during the Middle Cambrian period, about 505 million years ago. These arthropods lived on the sea bottom (epifaunal) and lived off dead particulate organic matter (a lifestyle called detritivorous).