Early Devonian animals

Jaekelopterus is an extinct genus of eurypterid, a group of extinct aquatic arthropods. Fossils of Jaekelopterus have been discovered in deposits of Middle Silurian to Early Devonian age, from the Wenlock epoch to Emsian stage.' There are three known species:' the type species J. rhenaniae from Devonian brackish to fresh water strata in the Rhineland, J. howelli from Devonian estuarine strata in Wyoming, and J. marylandicus from Silurian deposits in Maryland. The generic name combines the name of German paleontologist Otto Jaekel, who described the type species, and the Greek word () mean

Aayemenaytcheia paragranulata is a Middle Devonian proetid trilobite.

Janusiscus schultzei is an extinct gnathostome vertebrate dating from the Early Devonian period in Siberia, approximately 415 million years ago. It may be the sister group of the last common ancestor of Chondrichthyes (cartilaginous fish) or Osteichthyes (bony fish). This makes J. schultzei a sister species to all living jawed vertebrates. The species name is in honor of Hans-Peter Schultze; the genus named after Janus, the Roman god of duality.