Cranial material from a new genus (Ramphastosula) of Sulidae is described. The material comes from the Early–Lower Pliocene of the Pisco Formation of the central-southern coast of Peru. The skulls are characterized by (1) remarkable convex curvature of the dorsal surface and straight ventral surface of the rostrum, only with a curvature on the third anterior part and the tip of the bill; (2) well developed occipital and temporal regions; (3) broad opisthotic process projecting to the level of postorbital processes; (4) broad temporal fossa, and (5) flat braincase and robust frontal region.