New mosasaurs (Reptilia: Squamata) from the Scaglia Rossa Veneta Formation (Upper Cretaceous, Lessini area, Italy).

So far undescribed mosasauroid material is reported from the Turonian-Coniacian of Northern Italy (Lessini Mountains). The mosasaurs were collected from units of the Scaglia Rossa Veneta Formation, and more precisely within the lithozone informally known as the “Lastame”, an assemblage of well-bedded, reddish, often nodular marly limestones. The vertical extension of this lithozone in the area is usually less than ten meters, and has been related, as the rest of the formation, to a pelagic sedimentation on a submerged plateau, the Trento Plateau (Bosellini et al. 1978). Even if the Scaglia Rossa Veneta Formation is a unit spanning through the Turonian up to the Maastrichtian, Lozar & Grosso (1997) managed to date the “Lastame” subunit to the uppermost Turonian-Coniacian on the basis of the tintinnids and planktonic foraminifers biozones. The material is curated in two collections: The Natural History Museum in Verona and the Paleontological Museum in Sant’Anna di Alfaedo. The specimen in Verona (MCSNV V7481) includes the right and left maxillae, the right dentary, the frontal, and the posterior end of the lower jaw (surangular + articular complex), while the specimens in Sant’Anna di Alfaedo are represented by a very well preserved but fragmentary skull (IGVR 4224), and by an almost complete but badly preserved skull and postcranial skeleton (IGVR 4301). On the basis of the unique combination of anatomical characters (e.g. tooth morphology and number, shape of the frontal, quadrate, maxillary and dentary) the preserved material cannot be directly referred to any known mosasaur species and may represent two different species and a new genus. After being compared with specimens that can be considered representative of all the different mosasaur subfamilies, these Turonian-Coniacian mosasaurs show marked anatomical similarities to the basal Russellosaurina, as for example the recently described Russellosaurus coheni Polcyn & Bell, 2005. References:Bosellini A., Broglio-Loriga C. & Busetto C., 1978. I bacini cretacei del Trentino. Rivista Italiana di Paleontologia e Stratigrafia, 84: 897-946.Lozar F. & Grosso F., 1997. Biostratigrafia della successione cretacica del margine dei lessini occidentali (Provincia di Verona, Italia). Bollettino del Museo Regionale di Scienze Naturali, Torino, 15: 111-136.Polcyn M.J. & Bell G.L.Jr., 2005. Russellosaurus coheni n. gen., n. sp., a 92 million-year-old mosasaur from Texas (USA), and the definition of the parafamily Russellosaurina. Netherlands Journal of Geosciences, 84: 321-333.