This beast was South America's top predator before dinosaurs

This creature weighed around 400 kg

The exquisitely preserved fossilized specimen includes an intact skull and some ribs and arm bone remains. The fossils were discovered embedded in rocks dating to the middle Permian era. 

“Finding a new Pampaphoneus skull after so long was extremely important for increasing our knowledge about the animal, which was previously difficult to differentiate from its Russian relatives,” said Mateus A. Costa Santos, lead author from the Federal University of Pampa (UNIPAMPA). 

This species' lineage may be traced back to the early therapsid clade known as dinocephalians —  a word that means "terrible head" in Greek. Their distinctive trait was their massive skull bones, which earned them this name. 

The largest members of this group could potentially grow to almost three meters in length with a weight of approximately 400 kilograms.

Apart from this described specimen, the researchers also collected some additional species' fossil remnants from the same isolated Pampa location. These remains may belong to animals Pampaphoneus possibly preyed upon before its demise. Among these remains are those of the small dicynodont Rastodon and the giant amphibian Konzhukovia.

The diverse dinocephalian group existed just before one of the Earth's biggest mass extinction events, which wiped off as many as 86 percent of all animal species. 

“Its discovery is key to providing a glimpse into the community structure of terrestrial ecosystems just prior to the biggest mass extinction of all time. A spectacular find that demonstrates the global importance of Brazil’s fossil record,” added Pierce. 

Before their unfortunate extinction, dinocephalians constituted one of the most diverse groups of large land-dwelling creatures during their era — with some being carnivores and others herbivores.

Although widespread in South Africa and Russia, dinocephalians were scarce in other parts of the world. In Brazil, Pampaphoneus biccai stands as the sole known species of dinocephalian.

Pierce said: “Its discovery is key to providing a glimpse into the community structure of terrestrial ecosystems just prior to the biggest mass extinction of all time. A spectacular find that demonstrates the global importance of Brazil’s fossil record.”

Only two documented evidence of this species 

Interestingly, this is not the first instance of a Pampaphoneus skull being unearthed in South America. In fact, this marks the discovery of the second Pampaphoneus species skull fossil in South America, which is the most complete one. 

This 40-centimeter skull is notably larger than the previous one. The team was able to explore the intricate skull anatomy of this predator thanks to the extraordinary fossil preservation.

“Pampaphoneus played the same ecological role as modern big cats. It was the largest terrestrial predator we know of from the Permian in South America. The animal had large, sharp canine teeth adapted for capturing prey. Its dentition and cranial architecture suggest that its bite was strong enough to chew bones, much like modern-day hyenas," said Pinheiro. 

Some evidence suggests the existence of even larger members of this species. This information was gleaned from a jaw fragment belonging to the third member of the Pampaphoneus species. 

However, the fossil fragments have yet to be scientifically examined to be identified as Pampaphoneus.

The authors conclude that the evolving story of Pampaphoneus biccai, coupled with other fossil findings in the area, highlights the untapped potential of the Pampa region as a valuable source of the ancient world.

The results have been published in the Zoological Journal of the Linnean Society. 

Study abstract:

The Anteosauridae (Dinocephalia) were the largest predators of Guadalupian (Middle Permian) land communities. The, thus far, only known South American anteosaurid is the medium-sized syodontine Pampaphoneus biccai. This taxon was, until now, known only by its holotype, recovered from an outcrop of the Rio do Rasto Formation, Southern Brazil. Here we describe in detail an almost complete Pampaphoneus biccai skull associated with a few postcranial remains (UNIPAMPA 759) recently recovered from the type locality. The novel morphological information provided by this novel, better-preserved, specimen revealed that most characters previously proposed to distinguish Pampaphoneus biccai from Syodon biarmicum are probably ontogenetically constrained. We identify, however, new features that clearly distinguish these two taxa, and provide an updated diagnosis for Pampaphoneus biccai. Our phylogenetic reassessment of the taxon echoes previous propositions in which Pampaphoneus biccai was recovered as an early-divergent Syodontinae. Additionally, we tentatively indicate that a larger fragmentary specimen (UFRGS-PV-0249-P) may represent the mature size of the species, with the similar-sized holotype and UNIPAMPA 759 probably representing subadult individuals.