FIRST REPORT OF CLADOCORA ARBUSCULA IN EARLY PLEISTOCENE DEPOSITS (WESTERN UMBRIA, ITALY) AND ITS RELATIONSHIPS WITH THE DISTRIBUTION OF CLADOCORA CAESPITOSA

Corals ascribed to the species Cladocora caespitosa (Linnaeus, 1767) and secondarily to sister taxa are widespread in the present-day Mediterranean Sea. Although C. caespitosa was documented from Pliocene onward, it was commonly correlated to the Tyrrhenian (Marine Isotopic Stage 5, MIS5), particularly in the Italian fossil record. In many cases, the presence of C. caespitosa alone was considered a datum event marking the Pleistocene. In early Pleistocene deposits of Western Umbria, central Italy, several Cladocora horizons were recognized. The first known record of Cladocora arbuscula (Le Sueur, 1820) in early Pleistocene clay to sand deposits is presented here, and this also represents the first fossil datum of the species from the whole Mediterranean area. Inside deposits related to rocky coast environment, the two species coexisted. The paleoecology seems to be different for the two species, as C. caespitosa colonies develop in the shoreface and/or the beachface, while C. arbuscula prefers the distal and less energetic “transition to offshore” environment. Nevertheless, their occurrence records the same depositional phases during the evolution of the rocky coast. Like C. caespitosa, C. arbuscula probably formed small patchreefs during transgressive and high-stand system-tracts.