Scientists have unearthed fossils of a large carnivorous dinosaur that roamed northern Italy roughly 198 million years ago.
The researchers said that Saltriovenator zanellai was about 25 feet long and weighed at least a ton, which meant that it lived early in the Jurassic Period, and was known to be the largest carnivorous dinosaur that had ever existed.
Cristiano Dal Sasso? and Simone Maganuco from the Museo di Storia Naturale di Milano, Milan, and Andrea Cau from the Museo Geologico, Bologna, carried out the research. The study has been published in PeerJ.
The discovery pushes the known existence of big predator dinosaurs back by 25 million years, though in later periods it was succeeded by even bigger dinosaurs.
This unique specimen, which also represents the first dinosaur from the Jurassic period from Italy, was accidentally discovered in 1996 by a fossil amateur at a quarry near Saltrio, some 80 kilometres north east of Milan. Though first discovered in 1996, it took more than 20 years to extract the fossils from huge slabs of rock and to subject them to detailed analysis.
Many bones of Saltriovenator have feeding marks by marine invertebrates. This indicates that the dinosaur carcass floated in a marine basin. It then sunk and remained at the bottom of the sea for quite a long time before burial.
What has the study found?
After dying, the Saltriovenators carcass somehow floated into the sea and sank to the bottom, where it was scavenged over a period of months or years by several marine creatures before fossilising, the researchers said.
This is absolutely unique, said Milan Natural History Museum paleontologist Cristiano Dal Sasso, the lead author of the research. In scientific literature, there is mention of some dinosaur bones scavenged only by terrestrial animals, such as other dinosaurs, and, more rarely, insects. At least three kinds of marine animals left those traces on the bones of Saltriovenator, as per a Reuters report.
The paleontologists found 130 bone fragments, including pieces of the creatures jaw, ribs, pectoral bones, and a single tooth. 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,” Dal Sasso said.
What do we know about Saltriovenator?
Saltriovenator, which combined traits of primitive meat-eating dinosaurs with those of more advanced ones, indicated a succession of even bigger predatory dinosaurs that lived later during the Jurassic and in Cretaceous Periods.
Saltriovenator zanellai, meaning hunter from Saltrio, walked on two legs, had a skull that was two and a half feet long (80 cm) studded with sharp serrated teeth. It had fore limbs with four fingers, three of which possessed claws. The second half of the name is a tribute to Angelo Zanella, the amateur fossil hunter who found the dinosaurs remains while exploring the quarry in 1996.
The dinosaur was known to have lived in a coastal, humid environment in what is today the northern Italian region of Lombardy.
The predatory dinosaur was about 24 years old when it died, which means that it had not fully grown.
“Paleohistological analysis indicates that Saltriovenator was a still growing subadult individual, therefore its estimated size is all the more remarkable, in the context of the Early Jurassic period,” the studys co-author Simone Maganuco said.
“The evolutionary ‘arms race’ between stockier
predatory and giant herbivorous dinosaurs, involving progressively larger
species, had already begun 200 million of years ago.”
Elton Gomes is a staff writer at Qrius