Carboniferous arthropods

The Mesothelae are a suborder of spiders (order Araneae). The division of extant members of the suborder into families has varied. A single extant family Liphistiidae may be accepted, with two subfamilies: Liphistiinae, containing only the genus Liphistius, and Heptathelinae, with seven genera. Alternatively, the two subfamilies may be treated as separate families, Liphistiidae and Heptathelidae. , the World Spider Catalog accepted the single family approach. There are also a number of extinct families.

Euproops is an extinct genus of xiphosuran, related to the modern horseshoe crab. It lived during the Carboniferous Period.