The crustacean microcoprolite Palaxius floridanus n. isp. is described from shallow-water carbonate platform deposits of Pleistocene limestones of south Florida. Palaxius floridanus n. isp. occurs in moderate-energy packstones and grainstones of the oolite facies of the Miami Limestone, and in skeletal packstones of the Key Largo Limestone, ranging in age from marine isotope stage (MIS) 11 to MIS 5a (ca. 400–80 kyr BP). The new ichnospecies resembles P. decemlunulatus, which has been described previously from Oligocene deposits. Late Jurassic and Late Cretaceous forms described as P. decemlunulatus belong to a new ichnogenus and new ichnospecies, respectively, yet to be described.