The features of areal distribution and stratigraphic confinement of calcareous spicular sponge forms in the southeast of East European Platform are considered. The skeletons of calcareous sponges essentially representatives of the genus Porosphaera are found in the carbonates of Turonian, Coniacian, Campanian and Maastrichtian, as well as at the base of siliceous formations of the Paleocene. The Maastrichtian calcareous sponges are characterized by the highest species diversity and a wide lateral extension.
