Bioerosion in an equatorial Middle Jurassic coral-sponge reef community (Callovian, Matmor Formation, southern Israel)

摘要

The Matmor Formation (Middle Jurassic, Callovian, 165-161 mya) in southern Israel contains abundant coral-sponge patch reefs and large crinoids which have been extensively bioeroded by bivalves, worms, barnacles, phoronids, and others producing eight ichnospecies. It is significant for the evolutionary history of bioerosion because this is the first equatorial Middle Jurassic boring ichnofauna to be documented. When compared to contemporaneous ichnofaunas, this assemblage is of average diversity and abundance but has only rare sponge borings and contains abundant specimens of Oichnus paraboloides as shallow pits on crinoid stems. The Matmor Formation surprisingly lacks carbonate hardgrounds, which are otherwise abundant in subtropical and temperate equivalents.