Fossil find reveals skunk-sized predator roamed Egypt 34 million years ago

Scientists have discovered a small, skunk-sized mammalian carnivore with a fearsome set of teeth that likely preyed on human ancestors.

Masrasector nananubis lived in swampy, marshy environment

A fossil sample and x-ray of Masrasector nananubis. (Matt Borths)

Scientists have discovered a small, skunk-sized mammalian predator with a fearsome set of teeth that roamed what is now modern-day Egypt 34 million years ago.

In a paper published in PLOS ONE, scientists detail Masrasector nananubis, a land-dweller with muscular legs like a Rottweiler. Masrasector translates to "the Egyptian slicer" and Nananubis comes from Anubis, Egyptian god of the afterlife and mummification depicted with a canine head.

While Masrasector was known to science for decades, a recent dig in Egypt found several nearly complete skulls, jaws, and fragments of arm bones.  

Researchers say the new find is a member of the now-extinct hyaenodont family, a group that superficially resembled hyenas. They were the apex predators in Africa following the extinction of the dinosaurs, says Matthew Borths, of Ohio University.

Borths, one of the study authors, said in an interview with CBC News that hyaenodonts ranged in mass from "a weasel to a gigantic rhinoceros size."

Swampy, marshy environment

Unlike the bone-dry desert where it was found, Masrasector lived in a time when Egypt was a swampy, marshy environment resembling the Everglades of Florida.  An expanding Mediterranean Sea split Africa from the Eurasian mainland, leading to "weird animals that evolved in isolation," said Borths.

Some examples include an animal that resembled a cross between a hippopotamus and a pig, and ancient elephants that would look exotic today.

Masrasector also came with an unexpected development.

"It is part of a lineage of hyaenodonts that aren't specialized meat-eaters," says Borths.

The teeth of Masrasector resembled the generalist type, teeth that can grind down both meat and vegetation. By comparing the teeth of Masrasector to animals like a mongoose or skunk; animals that mix in fruits and seeds with vertebrate prey, they concluded Masrasector was likely omnivorous.

The remains of primates with distinctive teeth marks on the bones were also found at the site in Egypt's Fayum Depression, leading researchers to believe that Masrasector possibly preyed on the monkey-like ancestors of humans, along with mammals like hyraxes and large rodents.

Carnivore questions

The discovery of generalist teeth raises questions about the long-term survival and eventual disappearance of the hyaenodonts. Despite being successful predators that hunted in what is now Africa, Asia, Europe and North America as far back as 40 million years ago, they were eventually uprooted by the carnivorans, mammals that include today's dogs and cats, bears and seals.

The extinction of Masrasector is especially puzzling, researchers say. Given it followed a diet that mixed in vegetation, researchers thought it would be expected to have had a better chance at survival.

Borths suggests one possibility, saying Masrasector's muscular legs may not have been able to adapt as the African environment changed from swamps to grassland.

He says the Masrasector find could have implications today, because carnivores tend to go extinct first in a food chain.

"By understanding the extinction of a group like hyaenodont, we can understand the possible extinction of modern carnivores, and how to prevent it."