The Sedimentologic and Paleoecologic Significance of Lithotrya, a Rock-Boring Barnacle

ABSTRACT The rock-boring lepadomorph barnacle Lithotrya is a vigorous agent of bioerosion in the littoral zone of tropical seas, but few geologists are aware of its existence or its environmental significance. Lithotrya is commonly found in patchy exposures of beach rock around the island of Icacos, Puerto Rico, where it burrows upwards into overhanging ledges. The organism creates easily recognizable oval burrows and is important in the production of bioclastic sediments. Barnacles of the family Scalpellidae range back to the Triassic, yet no fossil examples of Lithotrya borings have been reported.