The deposits where the holotype specimen of "P. kopaninensis" was found preserves fossils of many other animals as well. Among them are trilobites such as "Leonaspis", "Raphiophorus" and a fragmentary harpetid trilobite. Also preserved are bivalves, such as "Cardiola", and graptolites, such as "Monograptus". "Pterygotus" most typically occurs in ecosystems with diverse eurypterid faunas, "P. lanarkensis" of the Kip Burn Formation of Scotland occurs together with several other eurypterid genera; "Slimonia", "Eusarcana", "Nanahughmilleria", "Parastylonurus", "Erettopterus" and "Carcinosoma". "P. impacatus" from Estonia occurs together with genera "Erettopterus", "Erieopterus", "Carcinosoma", "Mixopterus", "Dolichopterus" and "Eysyslopterus" as well as cephalaspidomorph fishes. "P. monroensis" lived alongside "Mixopterus", "Hughmilleria", "Eurypterus" and "Carcinosoma". "P. nobilis" lived alongside representatives of "Acutiramus", "Erettopterus" and "Eusarcana" as well as with a diverse fauna of conodonts, gastropods, cephalopods, ostracods, malacostracans, trilobites and bivalves and cartilaginous fish "Onchus".