Reappraisal of the Eocene whiptail stingrays (Myliobatiformes, Dasyatidae) of the Bolca Lagerstätte, Italy

The Eocene whiptail stingrays of the family Dasyatidae from the Bolca Lagerstätte, NE Italy, are revised herein in detail. The analysis of the anatomical and morphometric features allows us to identify the species “Dasyatis” zigni (Molin, 1861) as a junior synonym of “D.” muricatus (Volta, 1796), and to assign it to the new genus Tethytrygon gen. n. This new taxon exhibits a unique combination of features (e.g., rhombic disc wider than long, elongated tail folds fail to reach the tip of the tail, thorns absent, single serrated tail sting, “caniniform” teeth on upper jaw, tooth crown ornamentation absent, 175–179 vertebrae, 108–117 pectoral radials, 24–27 pelvic radials and other features of clasper anatomy) that clearly support its attribution to the subfamily Neotrygoninae of the stingray family Dasyatidae. The morphological and phylogenetic affinities of Tethytrygon gen. n. with the living neotrygonines (Neotrygon and Taeniura) suggest a close association of this taxon with the tropical shallow‐water habitats hypothesized for the Bolca palaeoenvironment during the early Eocene. Moreover, the analysis of the fossil occurrences of the neotrygonines provides new insights into the role of the Tethys for the origin and evolutionary history of certain whiptail stingrays.© 2018 The Author

The Effect of the Deepwater Horizon Oil Spill on Two Ecosystem Services in the Northern Gulf of Mexico

The Deepwater Horizon (DWH) oil spill likely affected ecosystem services in the Gulf of Mexico. To test this hypothesis, we configured a “Ecopath with Ecosim” model and quantified the effects of commercial fisheries and particulate organic carbon (POC) sequestration from 2004 to 2014, encompassing DWH. The yield of five functional groups were used to calculate changes in fishery catch and detritus biomass as a proxy for carbon buried offshore to calculate POC sequestration. The model predicted an estimated loss of $15–16 million per year (−13$20 million per year (11%) in the other four groups from 2010 to 2012. Model simulations estimated a loss of $1200 (−0.15%) in the ability of the Northern Gulf of Mexico offshore environment to sequester POC in 2010. The DWH simulation led to an increase in fisheries overall and decrease in POC sequestration ecosystem services in 2010