Sponge spicules found in Eocene, Oligocene, and middle Miocene sediments at DSDP Leg 71 Sites 511,512, and 513 belong to two classes; Hyalospongiae and Demospongiae. On the basis of spicule types and stratigraphic characteristics, spicule assemblages are distinguished for the lower and upper units of the middle Eocene, the upper Eocene, the lower Oligocene, the lower and upper units of the upper Oligocene, and the middle Miocene. In addition, 23 types and 76 dimensional varieties of spicules are described.

Supplement to: Ivanik, Mikhail M (1983): Paleogene and Neogene sponge spicules from Sites 511, 512, and 513 in the South Atlantic. In: Ludwig, WJ; Krasheninnikov, VA; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 71, 933-950