Potential Lagerstätte-type beds in the Upper Cretaceous of the Salento Peninsula (Apulia, Italy)

The recovery of an exceptionally well preserved pythonomorph lizard from the Apulian Platform (southern Italy), together with other well-preserved and undescribed vertebrate remains in the collections of the Natural History Museum of Verona from the same deposits, led to an investigation of some interesting but so far understudied fossil localities in southern Italy. The deposits of interest outcrop on the Salento Peninsula (Apulia) and are Upper Cretaceous in age. They are particularly famous for the abundance of a well-preserved and characteristic ichthyofauna. Other well-preserved vertebrates have been recovered from the same localities, but are still undescribed. The geology of this area has been poorly investigated and the resolution of the geological datum on a regional scale is untrustworthy; the stratigraphic age of these fossil-rich horizons is dated as Campanian- Maastrichtian according to the biostratigraphy (nanoplankton, rudists), or Santonian- Coniacian based on isotopes. In order to improve our knowledge of the geology of the area, we carried out sedimentological studies (facies analysis and composition) intended to identify the most fossiliferous beds. The new pythonomorph lizard was recovered from a small outcrop outside the town of Nardò (Lecce, Apulia), is the first complete basal pythonomorph (Squamata, Dolichosauridae) from southern Italy, and is particularly important since both mineralized scales and muscles are preserved together with the skeleton. The fossil is extremely important also for stratigraphic and palaeogeographical reasons: it significantly extends the temporal range of dolichosaurs from the Cenomanian-Turonian boundary to possibly the Coniacian-Santonian, or even as young as the Campanian-Maastrichtian. This new specimen fills the palaeogeographical gap in the fossil record of basal pythonomorphs of the Tethyan realm – described material since now was from the Mediterranean of Africa (Lebanon), the Dalmatian Domain (Croatia, Slovenia), and southeast England. This project aims to understand the stratigraphic relationships and palaeoenvironmental conditions characterizing these vertebrate-rich deposits, very likely with important repercussions on both the palaeogeography and geodynamics of the Mediterranean portion of the Tethys. An improvement in the resolution of the palaeogeographic arrangement of the Apulian Platform during the Upper Cretaceous will also allow better understanding of the radiation and distribution of basal pythonomorphs (e.g., dolichosaurs), which seems to be restricted to the Western Tethys.