Archosaur (possibly theropod) teeth from the Norian (Late Triassic) of Lombardy (Northern Italy)

摘要

Three isolated teeth, from an outcrop of the Zorzino Limestone (Norian, Late Triassic) in the Bergamo Prealps (Lombardy, Northern Italy) are reported. The triangular blade-like shape with serrated edges reveals that they are archosaurian, but a more precise taxonomic assignment within archosaurs is more difficult because this kind of teeth occurs in different Norian archosaurs, such as phytosaurs, rauisuchians and theropods. A detailed comparison of these taxa revealed that shape, size and pattern of serration suggest that they do not belong to a phytosaur but rather to rauisuchian or perhaps to a coelophysid theropod. The serration density is closer to that of coelophysid theropods, which is different from that of other theropods and of rauisuchians, suggesting that these teeth may perhaps represent the oldest dinosaur skeletal remains found in Italy so far.