The Pleistocene Bivalvia of Rhodes

The island of Rhodes (Dodecanese Islands, Greece) preserves a remarkably fossiliferous succession of Pleistocene strata, which has attracted scientists and collectors for nearly 200 years. The account of the predominantly marine bivalve fauna, which we are giving here, is largely the result of ‘only’ 30 years of collection and study on Rhodes by the second author. Nevertheless, it is the most comprehensive compilation so far, with the total diversity of Bivalvia ranging in the order of 140 species (work in progress). Much of this diversity is preserved in parautochthonous shell accumulations in shallow to medium shallow water fine-grained siliciclastic deposits, but Rhodes has more to offer. The Pleistocene succession conserves a variety of palaeoenvironments, including fluvial channels, brackish-water mud- and sand-flats, high-energy foreshores, low-energy shallow-water settings and different deep-water environments, including cold-water coral reefs. Naturally, all these environments were inhabited by bivalves, whose shells are generally well preserved, and thus are key to decoding the palaeoecology of the respective habitats. Interestingly, what reads like a lateral transect from the coast into the deep is also a vertical transect, reflecting one large scale transgressive-regressive sea-level cycle, with three smaller-scale cycles superimposed. While our scientific endeavours are focused on a monographic documentation of the bivalve fauna, we are also exploiting its palaeoecological potential, in order to improve our understanding of Pleistocene life on and around Rhodes, and its development over time. Our samples are probably biased towards larger taxa, since screen washing was not consistently applied, and certainly, shallow water carbonate environments are underrepresented, due to the difficulty to extract fossils from limestone. Nevertheless, the uncovered environmental framework is complex and comprehensive, and emphasizes the importance of Rhodes for the study of the Pleistocene faunal development of the Mediterranean Sea.