Massive bulldog-faced dinosaur was like a T. rex on steroids

A newly discovered, as-yet unnamed abelisaurid cautiously approaches a watering hole, in this detail from an artistic representation of the ecosystem of the Bahariya Oasis in Egypt's Sahara Desert approximately 98 million years ago.
A newly discovered, as-yet unnamed abelisaurid cautiously approaches a watering hole, in this detail from an artistic representation of the ecosystem of the Bahariya Oasis in Egypt's Sahara Desert approximately 98 million years ago. (Image credit: Image by Andrew McAfee, Carnegie Museum of Natural History)

One of the world’s most dangerous prehistoric ecosystems just added another huge predator to its lineup. In the Bahariya Formation, a famous fossil site in Egypt’s Sahara Desert, a team of Egyptian and American paleontologists recently uncovered a huge fossil vertebra belonging to a newly described species of meat-eating abelisaurid dinosaur — a bipedal, carnivorous group that lived during the Cretaceous period (145 million to 66 million years ago). 

Like other abelisaurids, the newfound dinosaur had a shortened, bulldog-like face. And despite its ferocious appearance, this carnivore probably wasn’t the biggest, baddest boss to roam its stomping grounds.

"We’re about 99% sure that, unlike some of its relatives from other times and places, this particular abelisaurid was not at the top of its food chain," Matthew Lamanna, a paleontologist at the Carnegie Museum of Natural History in Pittsburgh and one of the researchers who discovered the dinosaur, told Live Science in an email.

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Though Lamanna and his fellow scientists found only a single bone, they were able to identify the fossil as an abelisaurid vertebra almost immediately, based on distinctive structures called epipophyses. "That’s a multisyllabic word that basically means 'sticky-outy bits on the top left and top right of the vertebra,'" Lamanna said. This abelisaurid is the first dinosaur of its kind to be discovered at the Bahariya Formation site. After running a computer-based analysis of the bone’s morphology, the team concluded that it belonged to a previously unknown species, which has yet to be given a scientific name. They published their findings June 8 in the journal Royal Society Open Science

An abelisaurid somewhat resembled a heavy-set Tyrannosaurus rex, only with even stubbier arms, Smithsonian Magazine reported. They roamed the Southern Hemisphere from the middle of the Jurassic period, about 170 million years ago, right up until the Chicxulub asteroid brought the Cretaceous to a screeching halt. Perhaps the most famous abelisaurid is the horned Carnotaurus, a Patagonian predator that reached 25 feet (7.6 meters) long, according to London's Natural History Museum. Its name is taken from the Latin words for "flesh" and "bull," and animated versions of this fearsome carnivore have appeared in Apple TV's "Prehistoric Planet" and in the "Jurassic Park" franchise (though, its portrayals display varying degrees of scientific accuracy). 

This abelisaurid neck vertebra from the Bahariya Oasis, Egypt is the first evidence of this dinosaur group to be found in that rich fossil site. (Image credit: Photo by Belal Salem, Mansoura University Vertebrate Paleontology Center/Ohio University/Benha University)

The researchers suspect that the newly discovered abelisaurid was smaller than Carnotaurus, likely reaching just 16 to 20 feet (5 to 6 meters) in length. And compared to the predators who shared its native habitat 98 million years ago, the newfound abelisaurid would have been a relative pipsqueak.

The Bahariya Formation was previously home to a uniquely predator-rich slice of prehistoric life. This once-vast mangrove swamp hosted numerous species of fish, turtles, snakes and dinosaurs. The newfound abelisaurid would have rubbed elbows (metaphorically speaking) with a T. rex lookalike known as Carcharodontosaurus; a mysterious giant therapod (bipedal, three-toed dinosaurs) called Bahariasaurus; the monstrous Spinosaurus, which had long and slender crocodilelike jaws and a sail growing from its back; and giant predatory fish and crocodilians.

Finding so many large predators living together in a single ecosystem is rare,  Lamanna said. "How this 98-million-year-old environment managed to support not one but four massive predatory dinosaurs remains a puzzle," he added.

The newly described fossil is now stored in the permanent collection of Mansoura University's Vertebrate Paleontology Center in Egypt. In the future, Lamanna and his coauthors plan to return to the Bahariya Formation and search for more bones from their abelisaurid — and maybe even give it a name.

"Hopefully more of this Bahariya beast will turn up sooner or later," Lamanna said. 

Originally published on Live Science.

Joanna Thompson
Live Science Contributor

Joanna Thompson is a science journalist and runner based in New York. She holds a B.S. in Zoology and a B.A. in Creative Writing from North Carolina State University, as well as a Master's in Science Journalism from NYU's Science, Health and Environmental Reporting Program. Find more of her work in Scientific American, The Daily Beast, Atlas Obscura or Audubon Magazine.