Devonian arthropods of North America

The order Trigonotarbida is a group of extinct arachnids whose fossil record extends from the late Silurian to the early Permian (Pridoli to Sakmarian). These animals are known from several localities in Europe and North America, as well as a single record from Argentina. Trigonotarbids can be envisaged as spider-like arachnids, but without silk-producing spinnerets. They ranged in size from a few millimetres to a few centimetres in body length and had segmented abdomens (opisthosoma), with the dorsal exoskeleton (tergites) across the backs of the animals' abdomens, which were characteristical

Uraraneida is an extinct order of Paleozoic arachnids related to modern spiders. Two genera of fossils have been definitively placed in this order: Attercopus from the Devonian of United States and Permarachne from the Permian of Russia. Like spiders, they are known to have produced silk, but lack the characteristic spinnerets of modern spiders, and retain elongate telsons.

Attercopus is an extinct genus of arachnids, containing one species Attercopus fimbriunguis, known from flattened cuticle fossils from the Panther Mountain Formation in Upstate New York. It is placed in the extinct order Uraraneida, spider-like animals able to produce silk, but which lacked true spinnerets and retained a segmented abdomen bearing a flagellum-like tail resembling that of a whip scorpion. They are thought to be close to the origins of spiders.

Erieopterus is a genus of prehistoric eurypterid found in Silurian to Devonian-aged marine and freshwater strata of North America. The genus contains three species from the Silurian to the Devonian.'''''''' Erieopterus'' is the only genus in the family Erieopteridae, part of the Dolichopteroidea superfamily.

Eusarcana (meaning "true flesh") is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Eusarcana have been discovered in deposits ranging in age from the Early Silurian to the Early Devonian. Classified as part of the family Carcinosomatidae, the genus contains three species, E. acrocephalus from Scotland and E. scorpionis and E. spiniferum from the United States.