These Prehistoric Predators With Absolutely Enormous Heads Roamed the Earth Before the Dinosaurs

The 248 million-year-old fossilized skull of a huge predator with an enormous head has been re-examined by scientists in a bid to learn more about these prehistoric hypercarnivores.

Erythrosuchids, meaning "red crocodiles" were predatory creatures that lived just after the Permo-Triassic mass extinction 252 million years ago—the worst mass extinction event in Earth's history. They could reach up to 16 feet in length and are believed to have been apex predators.

The oldest genus of this family is a Garjainia, which appeared in the Early Triassic, 251 to 247 million years ago. The first dinosaurs would not walk Earth for another four million years after this period ended.

Species of Garjainia are found in South Africa and Russia, with two assigned to the latter—Garjainia prima and Vjushkovia triplicostata. The former has been fairly well studied, but V. triplicostata, known from the partial skeletons of seven individuals, has not.

In a study published in Royal Society Open Science, Richard Butler, of the U.K,'s University of Birmingham, and colleagues have analyzed the skull of V. triplicostata to better understand it. Findings showed that rather than being two distinct species, V. triplicostata and G. prima are actually the same species. They also determined that, relative to its overall body size, these erythrosuchids had some of the largest heads of any reptiles—about a quarter of their total length.

"We don't know for sure why this was the case, but we hypothesize that it might have been linked to their role as the top predators in a number of Triassic ecosystems: having a big, powerful head and bite is likely to be useful in capturing prey," he told Newsweek.

Garjainia prima
Artist impression of Garjainia prima. These prehistoric creatures emerged in the Early Triassic, after the 'Great Dying' mass extinction event 252 million years ago. Artwork from Mark Witton

The team notes that other early archosauromorphs—the clade to whicherythrosuchids belonged—also appear to have disproportionately massive heads, potentially indicating "the invasion of hypercarnivorous niches by these groups following the Permo-Triassic extinction," the researchers wrote.

Butler added: "Hypercarnivores are animals with diets almost exclusively composed of meat. We hypothesize that large predators at the top of food chains might have proportionately larger and more powerful heads in order to help in capturing prey."

Garjainia would have been between 6.5 and 10 feet long—similar to Komodo dragons. How their huge heads would have affected their movement is not known. "These are bizarre animals, but much about their biology remains unstudied," Butler said. "They presumably must have had very powerful neck muscles to support such a massive head, but detailed studies of their muscles have not yet been done."

This, he said, is what they now hope to establish: "We're working on the rest of the skeleton (the postcranial skeleton) at the moment, aiming to understand its anatomy and reconstruct muscles. Longer term we'd like to understand more about the biology of these weird animals, through using approaches like computer modelling to understand how their skulls functioned."