Two new Eucalathis (Brachiopoda, Chlidonophoridae) species from the Pliocene of Italy and history of the genus in the Mediterranean

Eucalathis, a member of the brachiopod superfamily Cancellothyridoidea, is common in Recent seas. The 15 known species have an almost cosmopolitan distribution, but no known occurrence in the Mediterranean Sea. Despite the rich Recent record, very little is known about the geological history of Eucalathis. In the Mediterranean, two fossil species are known from the Miocene of Italy. Two additional Eucalathis species from the Neogene of Italy are identified: E. davidi sp. nov. from NW Italy (Marmorito, Early Pliocene), and E. dorae sp. nov. from Sicily (Altavilla, Late Pliocene). It proves that Eucalathis did not disappear from the Mediterranean after the Messinian Salinity Crisis. Based on the four known species, Eucalathis (probably apart from the Messinian Crisis) was present in the Mediterranean from the Middle Miocene to the Late Pliocene. Its disappearance is possibly related to the Pleistocene cooling. Currently, three species of Eucalathis occur in the NE Atlantic, near the entrance to the Mediterranean. However, they are unable to enter because the distribution of all three species is restricted to deeper environments than the average 300 m deep Gibraltar sill. The circulation pattern of the Gibraltar area also prevents deeper water Atlantic species from entering the Mediterranean.