An Egyptian-American study team has discovered a new type of large-bodied meat-eating dinosaur, known as a theropod, at a well-known fossil site in Egypt’s the Sahara Desert. The Bahariya Formation, which is exposed in the Bahariya Oasis of Egypt’s the Western Desert, contains the first known record of the abelisaurid group of theropods from a middle Cretaceous-aged (about 98 million years old) rock block known as the Bahariya Formation.
This location is famed for producing the original fossils of a number of famous dinosaurs, including the giant sail-backed fish-eater Spinosaurus, which were then destroyed during World War II. Abelisaurid fossils had previously been discovered in Europe and on many of today’s continents in the Southern Hemisphere, but never from the Bahariya Formation. In an article released today in the Royal Society Open Science, the team reports the Bahariya abelisaurid discovery.
Belal Salem, a doctoral student at Ohio University, led the study, which was based on work he started while at the Mansoura University Vertebrate Paleontology Center (MUVP) in Mansoura, Egypt.
A 2016 MUVP mission to the Bahariya Oasis discovered the fossil in question, a well-preserved vertebra from the base of the neck. The vertebra belonged to an abelisaurid, a bulldog-faced, small-toothed, tiny-armed theropod with a body length of around six metres (20 feet). During the Cretaceous Period, the final time period of the Age of Dinosaurs, abelisaurids—most notably represented by the horned, demonic-looking Patagonian form Carnotaurus of “Jurassic World” and “Prehistoric Planet” fame—were among the most diverse and geographically widespread large predatory dinosaurs in the southern landmasses.
The new abelisaurid fossil joins Spinosaurus and two other big theropods (Carcharodontosaurus and Bahariasaurus) in the assemblage of large predatory dinosaurs that inhabited what is now the Egyptian Sahara around 98 million years ago.
“The Bahariya Oasis would’ve been one of the most horrific locations on the earth throughout the mid-Cretaceous,” says Salem, a recent graduate student in Ohio University’s biological sciences program. “How all these massive predators managed to coexist is a mystery, though it’s presumably related to the fact that they ate various foods and adapted to seek different prey,” says the author.
The new vertebra has implications for Cretaceous dinosaur biodiversity in Egypt and the entire northern African region. It is the earliest known Abelisauridae fossil from northeastern Africa, and it demonstrates that during the mid-Cretaceous, these predatory dinosaurs roamed most of the northern section of the continent, from present-day Egypt to Morocco, and maybe beyond. Niger and Morocco have also produced Spinosaurus and Carcharodontosaurus, as well as a close relative of Bahariasaurus, implying that this fauna of large to giant theropods coexisted throughout much of northern Africa at the time.
How does the discovery of a single neck vertebra lead experts to believe that the fossil belongs to a member of the Abelisauridae, a carnivorous dinosaur family that has never been discovered before in the Bahariya Formation? The answer is surprisingly simple: it’s nearly identical to the same bone in other, more well-known abelisaurids like Argentina’s Carnotaurus and Madagascar’s Majungasaurus. Patrick O’Connor, a collaborator and Salem’s graduate advisor who published a thorough study of Majungasaurus spinal architecture in 2007, notes, “I’ve studied abelisaur skeletons all over the world, from Patagonia to Madagascar. My initial glance at this specimen from the images convinced me that it was the one I was looking for. The neck bones of Abelisaurids are very unique.”
The Bahariya Oasis is well-known in paleontological circles for producing the type specimens (first-discovered, name-bearing fossils) of a number of remarkable dinosaurs in the early twentieth century, most notably Spinosaurus. Unfortunately, following an Allied bombing of Munich in 1944, all Bahariya dinosaur fossils gathered previous to World War II were destroyed.
Matt Lamanna, study coauthor and a doctoral student in the early 2000s, assisted in the discovery of the first dinosaurs from the oasis since the infamous 1944 air raid, including the massive sauropod (long-necked plant-eating dinosaur) Paralititan. “The Bahariya Oasis has gained a near-legendary reputation among paleontologists for producing the first-known fossils of some of the world’s most magnificent dinosaurs,” adds Lamanna, “yet those specimens have only survived as photos in old books for more than three-quarters of a century.”
Thankfully, discoveries produced by researchers from AUC and MUVP during recent excursions, such as the new abelisaurid vertebra, are helping to preserve the paleontological legacy of this historic site. These trips have unearthed a plethora of new fossils, which the experts aim to reveal in the near future.
“This bone is only the first of many important new dinosaur fossils from the Bahariya Oasis,” says team member Sanaa El-Sayed, who co-led the 2016 expedition that recovered the abelisaurid vertebra.
The Bahariya Formation has the potential to give further light on mid-Cretaceous African dinosaurs and their lost habitats. Unlike more extensively investigated rocks of the same age in Morocco, which tend to produce isolated bones, the Bahariya Formation appears to preserve partial skeletons of dinosaurs and other land-living creatures on a fairly regular basis. The more bones preserved inside a fossil backboned species’ skeleton; the more paleontologists can learn about it in general. The Bahariya Oasis’ proclivity for creating connected fragmentary skeletons shows that there is still a plenty to learn from this historic site.
“We’ve only scratched the surface in terms of Egyptian dinosaurs,” says study coauthorHeshamSallam. “Who knows what else is out there?” says the narrator. Professor Sallam and his international associates have recently made strides in involving Egyptian students in the research process. MUVP-based student researchers and contributing authors on the publication led both the field expedition that discovered the new abelisaurid fossil and the follow-up laboratory investigation. “Working with MUVP and its teachers and students, such as Belal Salem, continues to inspire me, as I watch the next generation of paleontologists taking a leading role in expressing their perspectives on the history of our planet,” O’Connor says.