The significance of the fossil Callianassid burrows occurrences for the paleoenvironmental reconstruction of the marine deposits has been fully emphasized in the literature. For the first time fossil burrows of these animals in the Cenozoic marine, probably Pleistocene, sediments from the State of Sao Paulo are discussed in some detail. The comparison with the same area living forms galleries permitted to assume that the fossil burrows were built by Callianassa major and Callianassa guassutinga, and that the first species was much more frequent than the second one, exactly as presently is observed.
