"eysyslopterus" is a little-known basal genus that was distinguished from the rest of adelophthalmids by the position near the head margin of the eyes, different from the rest of its relatives. its carapace was parabolic (approximately u-shaped) and with transverse deep furrows forming the ornamentation. with an estimated length of 8 cm (3.1 in), "eysyslopterus" was a small eurypterid. it lived in a nearshore lagoonal quiet community along other eurypterid species.