Blanquillos (Teleostei, Malacanthidae) from the Middle Miocene of St. Margarethen in Burgenland, Austria: Palaeoenvironmental implications

摘要

Fishes of the genus Malacanthus, also known as blanquillos are widespread circum-tropically in shallow waters with sandy bottoms. Blanquillos are diurnal territorial and sedentary fishes that build burrows in open and flat sandy areas near coral and rocky reefs and seagrass beds. The burrows are roofed by mounds constructed of shell and coral fragments, creating a peculiar habitat for benthic invertebrates and fishes on the sand-flat. A new species of blanquillo, dagger Malacanthus carosii sp. nov., is described from the Middle Miocene (Badenian, about 14 Ma) laminated marls of the Leitha Limestone cropping out in the nearby of the town of St. Margarethen in Burgenland, Austria. The three specimens of this Paratethyan taxon are the first articulated skeletons belonging to the malacanthid genus Malacanthus ever recorded as fossils. dagger M. carosii sp. nov. is typified by a unique combination of morphological and meristic features, including dorsal-fin with three or four spines and 48-49 rays, anal-fin with a single short spine and 44-45 rays, predorsal formula //2/1 + 1/, first haemal spine above the eighth anal-fin ray, and caudal fin emarginated. The presence of fishes of the genus Malacanthus in the laminated marls of the Leitha Limestone is indicative of a depositional depth located at about 30 m. The fossil record and the complex Cenozoic palaeogeographic and biogeographic history of the Tethys Realm concur to suggest that the modern fragmented distribution of blanquillo species probably originated during the Miocene, with the emergence of the Western Atlantic, Paratethyan, and Indo-Pacific species. (C) 2016 Elsevier Masson SAS. All rights reserved.