"Who are you saying has a big head?" Illustrations of Garjainia madiba, the erythrosuchid in this study. (Mark Witton/Wikimedia Commons)
Back between 250 million and 238 million years ago — at the start of the Triassic period — powerful reptiles ruled the landscape. They were called erythrosuchids (say eh-rith-roe-SUE-kids).
These weren't yet dinosaurs. (Their legs stuck out from the sides of their bodies like modern iguanas or alligators — dinosaur legs went straight below their bodies, like a bird's do.) But they were just as terrifying and deadly as their more famous cousins.
And according to a recent study of one erythrosuchid species, Garjainia madiba, they evolved to have a massive advantage over other predators of their time.
Huge, powerful heads.
A-head of the rest
The skull of Erythrosuchus africanus. Hollow spaces in the skull and powerful neck muscles allowed these animals to handle having such large heads. (Foth et al/Wikimedia Commons)
Erythrosuchids had exceptionally large heads compared to the rest of their bodies. We would call this a head-to-body ratio. In humans, the head-to-body ratio is about 1 to 8 — that means that you could stack eight heads in the total height of the human body (kind of weird, we know, but anyway...)
The head-to-body ratio of an erythrosuchid was even bigger than the most monstrous dinosaur predators like T. rex or Spinosaurus. These things were just enormous. How did they get this way? According to a study in Royal Society Open Science, these animals were just evolving to become the top predators of their time.
Making of a hypercarnivore
Crocodiles are modern relatives of erythrosuchids. See the resemblance? (Getty Embed)
Erythrosuchids were hypercarnivores — animals that survived by eating just meat. Their massive heads included large teeth and very powerful jaws. This made them a deadly opponent for the other creatures of the time. With dinosaurs still many millions of years away, there wasn't a creature around that could stack up against a hungry Garjainia.
Eventually these creatures went extinct. Later on, many dinosaur predators of the Jurassic and Cretaceous periods grew to have more agile bodies, rather than just brute force. But not all of the erythrosuchids big-head-first style went out of style.
The modern ancestors of these prehistoric beasts are the crocodilians — a group of stout, big-headed reptiles with a devastatingly strong bite. In fact, the word erythrosuchids means 'red crocodiles'. Guess everything comes back in style eventually!
