T-Rex’s meat-eating forefather lived in the Italian Alps, reveals new research.
Paleontologists have discovered the oldest ceratosaurian, which predates the massive meat-eating dinosaurs by over 25 million years and sheds light on the evolution of the three-fingered hand of birds.
Early Jurassic predatory dinosaurs are very rare, and mostly small in size.
Saltriovenator zanellai, a new genus and species described in the journal PeerJ, is the oldest known ceratosaurian, and, topping the scales at a ton, the world’s largest predatory dinosaur from the Lower Jurassic period.
The unique specimen, which also represents the first Jurassic dinosaur from Italy, was accidentally discovered in 1996 by a fossil amateur in a quarry near Saltrio, around 50 miles north east 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 a long time before burial.
Study first author Dr Cristiano Dal Sasso, reassembled and studied the fossil for several years.
Dr Dal Sasso, of the Natural History Museum of Milan, said: “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.”
Co-author Simone Maganuco said: “Analysis indicates that Saltriovenator was a still growing sub-adult individual, therefore its estimated size is all the more remarkable, in the context of the Early Jurassic period.
“The evolutionary ‘arms race’ between stockier predatory and giant herbivorous dinosaurs, involving progressively larger species, had already begun 200 million years ago.”
The evolution of the hand of birds from their dinosaurian ancestors is still hotly debated.
Co-author Dr Andrea Cau added: “The grasping hand of Saltriovenator fills a key gap in the theropod evolutionary tree: predatory dinosaurs progressively lost the pinky and ring fingers, and acquired the three-fingered hand which is the precursor of the avian wing.”
By Stephen Beech