Attercopus is an extinct genus of arachnids, containing one species Attacopus fimbriunguis, known from a Devonian-aged fossil. 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.