The continental bridge between Africa and Adria: new insights from the Lower Cretaceous of NW Sicily (Italy)

Abstract

Classic paleogeographic scenarios for the Cretaceous of the Central Mediterranean area depicted the peri-Adriatic region as punctuated by patchy carbonate platforms far from the main emergent lands. The increasing dinosaur record of African affinity in Italy questioned such palaeogeographic scenarios and suggests the proximity of landmass areas connecting Africa and Adria during Cretaceous times. Besides several track-sites and some exceptionally-preserved specimens, the Italian dinosaur record also consists of isolated bones, among which the fragment of a theropod bone discovered in NW Sicily (Capaci) in a carbonate succession pertaining to the Panormide Carbonate Platform (PCP). This bone fragment was previously referred to the Cenomanian and its occurrence strongly supports the hypothesis of a land bridge connecting Africa and Adria via PCP. More recently, new sedimentological and biostratigraphic data from this carbonate succession (i.e. Pizzo Muletta) have allowed to predate the chronostratigraphic position of the dinosaur bone to upper Aptian–lower Albian and to assess a detailed Aptian–Cenomanian evolution of this sector of the PCP. In particular, a karstic overprint has been observed thus indicating a subaerial exposure of the platform preceding its drowning in latest Cenomanian times. The obtained results extend the chronostratigraphic interval of the possible land bridge between Africa and Adria at least from Aptian to Cenomanian and highlight the progressive tectonic dismantling of this connection during the Late Cretaceous.