The oldest large-sized predatory dinosaur comes from the Italian Alps

Early Jurassic predatory dinosaurs are very rare, and mostly small in size. Saltriovenator zanellai, a new genus and species described in the peer-reviewed journal PeerJ - the Journal of Life and Environmental Sciences by Italian paleontologists, is the oldest known ceratosaurian, and the world's largest (one ton) predatory dinosaur from the Lower Jurassic (Sinemurian, ~198 Mya).

At the Natural History Museum of Milan, paleontologist Cristiano Dal Sasso (left) and co-authors Simone Maganuco
and Andrea Cau (center and right) examine the bones of Saltriovenator, deposited in the Museum collections
[Credit: Gabriele Bindellini]

This unique specimen, which also represents the first Jurassic dinosaur from Italy, was accidentally discovered in 1996 by a fossil amateur within a quarry near Saltrio, some 80 km N-E of Milan. Many bones of Saltriovenator bear feeding marks by marine invertebrates, which represent the first case on dinosaurian remains and indicate that the dinosaur carcass floated in a marine basin and then sunk, remaining on the sea bottom for quite a long time before burial.

Although fragmentary, "Saltriovenator shows a mosaic of ancestral and advanced anatomical features, respectively seen in the four-fingered dilophosaurids and ceratosaurians, and the three-fingered tetanuran theropods, such as allosaurids", says first author Cristiano Dal Sasso, of the Natural History Museum of Milan, who reassembled and studied the fossil for several years.