What do sharks, rays, and chimaeras have in common? All of these species have ampullae of Lorenzini. Ampullae of Lorenzini are sensory organs that allow certain animals to locate and capture their prey through the detection of electromagnetic fields. It was Stefano Lorenzini, an Italian biologist, who discovered these sensory organs during the 17th century. These receptors are indicated by small black dots located on the muzzle, on the skull and around the eyes of the animals.