A new specimen of Nothosaurus from the Anisian (Middle Triassic) Besano Formation (Grenzbitumenzone) of Italy.

A nearly complete but disarticulated skeleton of a small sized nothosaur is described The specimen was collected in 2003 from an outcrop of the Besano Formation (Grenzbitumenzone of Swiss authors) of latest Anisian (Middle Triassic) age, in the Monte San Giorgio Area, northern Italy The osteology of the postcianial skeleton supports the assignment to the genus Not bosom us, and also excludes Its belonging to Nothosaurus giganteus/Paranothosaurus amsleri already known from coeval localities of the Besano Formation in the Swiss part of the Monte San Giorgio :ilea Despite the lack of most of the skull, which contains diagnostic characters at the species level lot Nothosaurus, the few preserved cranial elements suggest similarities with N juvenilis which skull, and only known pair, is also of comparable size This specimen is particularly significant because it improves the knowledge of the osteology of N juvenilis and because the second Nothosaurus species, smaller than N giganteus/P amsleri, suggests coexistence of sympatric species characterized by size and, probably, trophic differentiation within the genus Nothosaurus in the Monte San Giorgio area as occurred m the coeval Germanic Basi