Dinosaurs like Tyrannosaurus rex lead the list of animals that we consider to be the most ferocious (predators that attack with aggression and fury) in the history of the Earth. The T.rex lived between 68 and 66 million years ago, at the end of the Cretaceous period.
Long before, 265 million years ago (Middle Permian), in the land area that now forms the pampas (South America), the most ferocious animal that humans have knowledge of was not a dinosaur, but a dinocephalian, specifically, the species which the scientists who found its first fossils (catalogued in 2012) called Pampaphoneus biccai (the first part of the name means 'killer of the pamapa' and the second refers to the owner of the farm where the fossil was found, José Bicca ).
In a new study published in the Zoological Journal of the Linnean Society, an international team of researchers reveals new data from Pampaphoneus biccai fossils found in recent years in the rural area of São Gabriel, southern Brazil.
The remains studied include a complete skull and some bones, such as ribs and arm bones.
P. biccai, which belongs to the clade of early therapsids called dinocephalians, lived before the Permian-Triassic Extinction (250 million years ago), a debacle (possibly caused by the natural combustion of coal in Siberia) that ended the life of up to 96% of marine species and 70% of terrestrial vertebrate species.
Before this catastrophe, dinocephalians were one of the main groups of land animals. They were medium to large sized creatures with both carnivorous and herbivorous representatives. Dinocephalians had thick cranial bones, which gave rise to the group's name, which translates to "terrible head" in Greek. While they are well known in South Africa and Russia, these animals are rare in other parts of the world. Pampaphoneus biccai is the only species of dinocephalian known from that area of the current pampas in Brazil.
"The fossil was found in rocks from the Middle Permian, in an area where bones are not so common, but they always hold pleasant surprises," said lead author Mateus A. Costa Santos, a graduate student in the University's Paleontology Laboratory. Federal of Pampa (UNIPAMPA). "Finding a new Pampaphoneus skull after so much time was extremely important in increasing our knowledge about the animal, which was previously difficult to differentiate from its Russian relatives."
Due to the pandemic, it took three more years to thoroughly clean and study the fossil. Co-author Professor Stephanie E. Pierce, in the Department of Organismic and Evolutionary Biology and Curator of Vertebrate Paleontology and Mammalogy at the Harvard Museum of Comparative Zoology, participated in the study of the animal as part of her current work with the senior author and Laboratory head Professor Felipe Pinheiro, UNIPAMPA, on the fossil record of the Permo-Triassic of Brazil.
"This animal was a twisted-looking beast, and must have evoked pure fear in anything that crossed its path," Pierce said. "Its discovery is key to glimpse the community structure of terrestrial ecosystems just before the largest mass extinction of all time. A spectacular find that demonstrates the global importance of Brazil's fossil record."
The new specimen is the second Pampaphoneus skull discovered to date. It is also larger than the first and provides unprecedented information about its morphology due to the exceptional preservation of its bones.
"Pampaphoneus played the same ecological role as modern big cats," Pinheiro said. "It was the largest terrestrial predator we know from the Permian in South America. The animal had large, sharp teeth adapted to capturing prey. Its dentition and cranial architecture suggest that its bite was strong enough to chew bones, much like to the modern hyena". To avoid improper interpretations, we prefer to avoid expressions such as the one used in some media in which it is stated that P. buccai was a "bloodthirsty predator" (a phrase that literally, according to the RAE, could be interpreted as "ferocious, vengeful" predator. , who delights in shedding blood."
Researchers estimate that the largest individuals of Pampaphoneus could reach almost three meters in length and weigh around 400 kg. It was a skilled predator capable of feeding on small and medium-sized animals. In the same locality where the fossil was found, some of its potential prey have also been identified, such as the small dicynodont Rastodon and the giant amphibian Konzhukovia, details Harvard University in an informative note presenting the results of this research.
The Pampaphoneus could certainly be ferocious but, compared to its size, it would not have been able to compete with the T.rex, which reached 12 meters long, five meters high and weighed between six and nine tons.