Diversity, palaeoecology and palaeoenvironmental significance of the Eocene chondrichthyan assemblages of the Bolca Lagerstätte, Italy.

Over the last few years, the morphology, taxonomy and systematics of the cartilaginous fish taxa of the two main sites of the Bolca Lagerstätte, Italy, (Pesciara and Monte Postale sites) have been extensively discussed in a series of papers, resulting in a complete revision of this neglected component of the Eocene Tethyan ichthyofauna. Here, we provide a comprehensive overview of the diversity, palaeoecology and palaeoenvironmental significance of the two chondrichthyan assemblages of the Pesciara and Monte Postale sites. The assemblages include 14 shark species (Lamniformes and Carcharhiniformes) and batoids (Torpediniformes, Rhinopristiformes, Myliobatiformes, Platyrhinidae and Zanobatidae), as well as a single putative chimaeriform.

A decline in molluscan carbonate production driven by the loss of vegetated habitats encoded in the Holocene sedimentary record of the Gulf of Trieste.

Carbonate sediments in non-vegetated habitats on the north-east Adriatic shelf are dominated by shells of molluscs. However, the rate of carbonate molluscan production prior to the 20th century eutrophication and overfishing on this and other shelves remains unknown because: (i) monitoring of ecosystems prior to the 20th century was scarce; and (ii) ecosystem history inferred from cores is masked by condensation and mixing. Here, based on geochronological dating of four bivalve species, carbonate production during the Holocene is assessed in the Gulf of Trieste, where algal and seagrass habitats underwent a major decline during the 20th century.