Trilobites are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian 展开

The study of Paleozoic trilobites in the Welsh-English borders by Niles Eldredge was fundamental in formulating and testing punctuated equilibrium as a mechanism of evolution. 展开

When trilobites are found, only the exoskeleton is preserved (often in an incomplete state) in all but a handful of locations. A few locations (Lagerstätten) preserve identifiable soft … 展开

Trilobite relatives
Trilobites belong to the Artiopoda, a group of extinct arthropods morphologically similar to trilobites, though … 展开

Trilobites appear to have been primarily marine organisms, since the fossilized remains of trilobites are always found in rocks containing fossils of other salt-water animals such as … 展开

The 10 most commonly recognized trilobite orders are Agnostida, Redlichiida, Corynexochida, Lichida, Odontopleurida, Phacopida, Proetida, Asaphida, Harpetida and Ptychopariida. In 2020, an 11th order, Trinucleida, was proposed to be elevated out of the asaphid … 展开

Only 21 or so species are described from which soft body parts are preserved, so some features (e.g. the posterior antenniform cerci … 展开