The first ophthalmosaurid ichthyosaur from the Upper Jurassic deposits of the Central–\ud Northern Apennines (Marche, Italy) is here described for the first time. The specimen is relatively\ud complete and is referred to Gengasaurus nicosiai gen. et sp. nov. based on a unique combination of\ud characters, including a peculiar condition of the preaxial accessory facet on the humerus. The faunal\ud association of the ichthyosaur-bearing level indicates a late Kimmeridgian – earliest Tithonian age,\ud and its finding contributes significantly to our knowledge of the diversity of Late Jurassic ichthyosaurs\ud from the Western Tethys. Two shark teeth assigned to the order Hexanchiformes were also recovered\ud in association with the ichthyosaur specimen, suggesting that scavenging of the carcass might have\ud occurred. Gengasaurus can be referred to Ophthalmosauridae based on the reduced extracondylar\ud area of the basioccipital, and the presence of a preaxial digit. It differs from Ophthalmosaurus spp.\ud in several respects, including the shape of the posterior basisphenoid, the shape of the supraoccipital,\ud the anteriorly deflected preaxial facet of the humerus, and a proximodistally shortened ulna. The new\ud taxon actually shares diagnostic characters with both members of the two main lineages recovered in\ud previous phylogenetic analyses,more nested within Ophthalmosauridae. The affinities of Gengasaurus\ud to genera from both the northern and southern hemispheres also suggest that connectivity between\ud pelagic habitats was high during the early Late Jurassic, allowing dispersal of some forms, followed\ud by local, endemic divergence

The spectacular karst morphologies of the area between Campoli Appennino and Alvito (Southern Lazio, Italy) represent an emblematic example of karst processes acting on different types of substrate. Hypogean forms are subordinated to epigean ones, with dolines as undiscussed leaders. Imposing and famous are the dolines of "Fossa Maiura" (also known as "Fossa Majura" or "Fossa Majora") and "Il Tomolo", around which the town of Campoli Appennino is built in a semi-circle, but are 8 the karst depressions with a diameter greater than 200 m ("main macrodolines") in this area. These forms of landscape controlled the cultural and socio-economic aspects of this corner of Ciociaria. Starting from the second half of the 19th century, the hydrogeological, structural, stratigraphic and geomorphological features of the Campoli Appennino area, attracted the interest of geologists, allowing to recognize a "site of geological memory". However, the geological heritage of this area worth greater visibility, as indicated by the poorly-developed geo-tourism, and for a greater dissemination, making the geo-morphological features more accessible and understandable, even for non-geologists.

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