NEW DATA ON THE EARLY JURASSIC BIODIVERSITY OF THE LOMBARDY BASIN (SOUTHERN ALPS, ITALY) AND THE EARLIEST RECORD SPHENODUS (CHONDRICHTHYES, NEOSELACHII)

At the beginning of the Jurassic, the initial stages of the rifting that preceded the opening of the Alpine Tethys led to the establishment of the Lombardy basin, characterized by a shallow water marine palaeoenvironment inhabited by highly diversified ecological communities. Macrofossil records from the whole Lower Jurassic succession of Lombardy are currently mostly confined to invertebrates. The earliest occurrence of marine vertebrates is from the Sinemurian Moltrasio Limestone of Osteno (Varese), subsequent to the Triassic/Jurassic boundary (TJB) post-crisis recovery. Here, we describe material from the Roncola section (Roncola San Bernardo, Bergamo) of the Sedrina Limestone (upper Hettangian), consisting of a dense accumulation of crinoid skeletal remains belonging to Balanocrinus ticinensis Hess, 2006. Among them are three isolated neoselachian teeth assigned to the genus Sphenodus Agassiz, 1843. This new discovery is significant and extends our knowledge of the biodiversity of the Lombardy basin Jurassic, mainly because these dental remains represent the earliest vertebrate macrofossils ever documented from this area after the Triassic/Jurassic boundary. Sphenodus (which ranges from the Sinemurian to the Danian) is a fairly ubiquitous Sinemurian neoselachian shark but this new record moves its First Appearance Datum (FAD) back to the Hettangian stage

MIDDLE TRIASSIC ECHINODERMS FROM THE SAN SALVATORE FORMATION OF LOMBARDY (ITALY) AND CANTON TICINO (SWITZERLAND)

An echinoderm fauna from the San Salvatore Formation (Middle Triassic, Southern Alps) is here  described in detail for the first time. Identifiable crinoids and echinoids were collected from three different localities: Mt. San Salvatore (Ticino, Switzerland), Rasa di Varese and San Michele (Lombardy, Italy). Crinoid taxa include Encrinus cf. aculeatus, Holocrinus sp. indet., Zardinicrinus cf. granulosus, Encrinidae gen. et sp. indet. Echinoid taxa include “Cidaris” cf. roemeri, Serpianotiaris sp. indet., Triadocidaris transversa, Triadocidaris sp. indet., and an indetermined form (Cidaridae). Most of the material was collected from Rasa di Varese, along with a rich upper Anisian ammonoid and conodont fauna, belonging to the upper Reitzi Zone and the Secedensis Zone. Migration of crinoids have been documented during the upper Anisian (from upper Pelsonian to lower Illyrian), mainly from the westernmost Tethyan Realm northward to the Germanic basin. Crinoid taxa already reported in the lower and upper Illyrian of the Germanic basin have also been collected, dated here to the late Illyrian (upper Reitzi Z.-Secedensis Z.) suggesting that several taxa migrated southwards in the Tethys realm during the late Illyrian