Extinct genus of spiders
Arthrolycosa (meaning "wolf [spider] with joints") is an extinct genus of arachnids, possibly spiders, that lived about 300-250 million years ago.
Fossils have been found Mazon Creek USA, Piesberg in Germany and in the Kirov Oblast region, and the Kamensk-Shakhtinsky of Russia.
"A. antiqua" is estimated to have a body length of about 2.17 cm and may have preyed upon insects and other smaller animals that lived alongside them. "A. wolterbeeki" is the oldest spider known from Germany.