A new species of a now-extinct carnivorous mammal from Egypt has been identified by scientists.
The animal, known as Masrasector nananubis, was once near the top of the African food chain and lived in the same swampy ecosystem that was home to our earliest monkey-like relatives.
The researchers suggest that our ancient ancestors could have once been hunted by Masrasector, according to Daily Mail.
The carnivore was a small, fox-like mammal that scrambled on the ground and ate large rodents and other small- or medium-sized mammals.
"Human ancestors that lived among the Masrasector were small and monkey-like," study lead author Matt Borths, a researcher at Ohio State University, told MailOnline.
"If one of these animals dropped to the ground from the trees they would have been targeted by the Masrasector.
"We've found fossilised bones of these human ancestors with teeth marks on them that could have come from a Masrasector or one of its close relatives."
Masrasector means "The Egyptian slicer" because the meat-eater was found in the deserts of Egypt, near the Fayum Oasis southwest of Cairo.
The species name, nananubis, means "tiny Anubis, because it resembles the jackal-headed ancient Egyptian god of the afterlife.
Researchers identified the new species using dozens of specimens, including multiple skulls, jaws, and limb bones.
Using these specimens the team examined what Masrasector ate, how it pursued prey, and how the earliest carnivores in Africa were related to each other.
Masrasector nananubis was part of an extinct group of carnivorous mammals called hyaenodonts.
Hyaenodonts were the only meat-eating mammals in Africa for more than 40 million years after the extinction of the dinosaurs, lasting until around seven million years ago.
African hyaenodonts are a rare find, and most are only known from a few isolated teeth and jaws.
But Masrasector is known from several nearly complete skulls, dozens of jaws, and pieces of arm bone.
"With all this material, we can really dig into what Masrasector ate, and how it moved through its environment," Mr Borths said.
"I've always been fascinated by African carnivores like lions and hyenas.
"Masrasector gives us a detailed view of how these other African carnivores pursued their prey and what their diet was like."
The specimens were discovered in a quarry called Locality-41, one of the most fossil-rich places from the beginning of the Age of Mammals in Africa.
The first specimens of Masrasector were found at L-41 nearly 30 years ago.
For decades, the specimens accumulated as Egyptian and American palaeontologists delicately removed the fossils from the salty, clay-like rock they were embedded in.
"This study is the result of hundreds of people moving sediment, preparing the specimens, and protecting these delicate fossils, which need to be kept in a humidity-controlled room because the salt and clay they were fossilised in can expand and break the bones," Mr Borths said.
With all the anatomical detail provided by the specimens, the researchers could run an analysis to understand where Masrasector fits in the hyaenodont family tree.
They found Masrasector is part of a group of hyaenodonts that were part of African ecosystems for millions of years.
The oldest species in the group is nearly 50 million years old and the youngest shared the landscape with the early relatives of dogs, cats, and mongooses that crossed into Africa when the Arabian Peninsula connected Africa to Eurasia.