Jaekelopterus ("Otto Jaekel's wing) is an extinct genus of sea scorpion. Jaekelopterus lived approximately 390 million years ago. At an estimated length of , it is the largest known arthropod ever discovered, surpassing even the famous millipede-like Arthropleura. There are two species, one being the type species, J. rhenaniae, from freshwater strata in the Rhineland, and J. howelli from estuarine strata in Wyoming.

Jaekelopterus ("Otto Jaekel's wing) is an extinct genus of sea scorpion. Jaekelopterus lived approximately 390 million years ago. At an estimated length of , it is the largest known arthropod ever discovered, surpassing even the famous millipede-like Arthropleura. There are two species, one being the type species, J. rhenaniae, from freshwater strata in the Rhineland, and J. howelli from estuarine strata in Wyoming.