A new kind dinosaur called “Erythrovenator jacuiensis” was recently discovered in the south Brazil and it was determined that he was one of the oldest ancestors of the Tyrannosaurus rex who lived about 230 million years ago.
The new specimen was also a predator, but smaller than the Tyrannosaurus Rex, and it ranks as one of the most primitive members of the theropod lineage. in turn belong to species such as the velociraptor.
The person responsible for the discovery is Brazilian paleontologist Rodrigo Temp Müller, of the Federal University of Santa María, who published the discovery in the Journal of South American Earth Sciences.
Müller identified the new species from a fossilized femur that he found in the summer of 2017 on a rural site in the municipality of Agudo, in the southern Brazilian state of Rio Grande do Sul.
“We had very few fossils on these dinosaurs, most of them were quite fragmented. This specimen that I discovered is just a bone, quite damaged, but it has features that can only be seen in the theropod lineage, ”explains Müller.
‘And within that line it belongs to an animal that we did not know until now. Despite being just a bone, it is possible to see features that we would not have seen in other dinosaurs, ”he adds.
“Erythrovenator jacuiensis” means “red hunter of the Jacuí river”. Müller gave it that name because of the reddish color of the fossil and because of the river that flows close to where it was discovered.
An analysis to identify the degree of relatedness revealed that the red hunter would be one of the dinosaurs of the theropod family that “have been most primitively discovered.”
A small but agile predator
The oldest theropods, which are particularly difficult to find, were all carnivores, so they estimate that the “Erythrovenator jacuiensis” also fed on flesh, despite the fact that no tooth or skull remains have been found so far.
“The Rex reached up to 12 meters in length and weighed about ten tons. This dinosaur was very small, it could reach a length of about two meters and it weighed little more than 10 kilos, ”explains Müller.
“This is very interesting because it shows that this line of famous dinosaurs, such as Tyrannosaurus Rex or Velociraptor, comes from a group of small dinosaurs,” he emphasizes.
Despite its small size, it was likely an extremely agile predator, as the fossilized femur has quite developed muscle attachment structures.
Although Müller only owns one femur, he managed to simulate its appearance from other studies of similar animals that are said to be close relatives and based on other material found in Argentina and the United States.
The “Niemeyer Site”, a new nest of fossils to be discovered
The discovery of this new species will help to understand the evolution of the group over millions of years and confirms that theropods, of which there is little data, have been present in South America since the dinosaurs’ origins.
The exact site where Müller found this new species is known as the “Niemeyer Site”, referring to the name of the family that owns the land that has now become a gold mine for paleontologists in the region.
Experts believe that a completely new fossil nest is being found at that geographic point, as other animals discovered in it were also unknown until now.
In fact, they have found remains at the site corresponding to mammalian relatives, which may have served as food for the “Erythrovenator jacuiensis”.
However, dinosaurs were quite rare in ecosystems at the time, as they dominated the Earth during the Jurassic and Cretaceous, that is, from 201 to 66 years ago.
Before that stage, they were not very representative and dominance was exercised by other older reptiles who became extinct at the end of the Triassic, about 201 million years ago.
Müller now hopes to continue the field work and the expeditions to find more complete material and assemble the puzzle of the dinosaur ancestors.