The Middle Eocene siliceous sponges from Val di Chiampo (Lessini Mountains, northern Italy)

Abstract

The Lower Lutetian hyaloclastites cropping out in the Val di Chiampo (Vicenza, northern Italy) contain
a very rich and diversified siliceous sponge fauna. In this paper we give preliminary determinations and
illustrations of 23 siliceous sponge species. The most abundant are the Lychniscosa, with ten species, followed
by Hexactinosa, with seven species, and Lithistida, with six species.
Twelve species are in open nomenclature, five are identical or similar to species described by Pisera and
Busquets (2002), from the Bartonian of the Ebro Basin (Spain), and five are compared with species described
by Pomel (1872) from the Miocene of Algeria. From a paleoecological point of view, it is supposed that the
sponge fauna inhabited the euphotic zone.