Paleontologists from the American University in Cairo and elsewhere say they have found an almost complete skull of the hyaenodont Bastetodon syrtos in the lower Oligocene layers of the Jebel Qatrani Formation, Egypt.

Bastetodon syrtos lived during the Oligocene epoch, some 30 million years ago, in the lush forest of Fayum, Egypt, which is now home to a desert.

Also known as Pterodon syrtos, the ancient species was about the weight (27 kg) of a hyena or leopard.

The animal had sharp teeth and powerful jaw muscles, suggesting a strong bite.

It had a hypercarnivorous diet, likely preying on primates, early hippos, early elephants, and hyraxes.

“Bastetodon syrtos belongs to a species in an extinct group of carnivorous mammals called hyaenodonts,” said Dr. Shorouq Al-Ashqar, a paleontologist at Mansoura University and the American University in Cairo, and colleagues.

“Hyaenodonts evolved long before modern-day carnivores such as cats, dogs, and hyenas.”

“These predators with hyena-like teeth hunted in African ecosystems after the extinction of the dinosaurs.”

The skull of Bastetodon syrtos was unearthed in the Jebel Qatrani Formation, Fayum Depression.

“For days, our team meticulously excavated layers of rock dating back around 30 million years,” Dr. Al-Ashqar said.

“Just as we were about to conclude our work, a team member spotted something remarkable — a set of large teeth sticking out of the ground.”

“His excited shout brought the team together, marking the beginning of an extraordinary discovery: a nearly complete skull of an ancient apex carnivore — a dream for any vertebrate paleontologist.”

“The Fayum is one of the most important fossil areas in Africa,” added Dr. Matt Borths, curator of fossils at the Duke Lemur Center Museum of Natural History at Duke University.

“Without it, we would know very little about the origins of African ecosystems and the evolution of African mammals like elephants, primates, and hyaenodonts.”

“The discovery of Bastetodon is a significant achievement in understanding the diversity and evolution of hyaenodonts and their global distribution,” Dr. Al-Ashqar said.

“We are eager to continue our research to unravel the intricate relationships between these ancient predators and their environments over time and across continents.”

In their research, the authors also reevaluated a group of lion-sized hyaenodonts that was discovered in the rocks of the Fayum over 120 years ago.

They established a new hyaenodont genus, Sekhmetops, to redescribe the 33.8-million-year-old material.

They demonstrated Bastetodon and Sekhmetops both belonged to a group of hyaenodonts that actually originated in Africa.

“The relatives of Bastetodon and Sekhmetops spread from Africa in multiple waves, eventually making it to Asia, Europe, India, and North America,” they said.

“By 18 million years ago, some relatives of these hyaenodonts were among the largest mammalian meat-eaters to ever walk the planet.”

“However, cataclysmic changes in global climate and tectonic changes in Africa opened the continent to the relatives of modern cats, dogs, and hyenas.”

“As environments and prey changed, the specialized, carnivorous hyaenodonts diminished in diversity, finally going extinct and leaving our primate relatives to face a new set of antagonists.”

The findings appear in the Journal of Vertebrate Paleontology.

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Shorouq F. Al-Ashqar et al. Cranial anatomy of the hypercarnivore Bastetodon syrtos gen. nov. (Hyaenodonta, Hyainailourinae) and a reevaluation of Pterodon in Africa. Journal of Vertebrate Paleontology, published online February 16, 2025; doi: 10.1080/02724634.2024.2442472