Evrim Yazgin
Cosmos science journalist
It’s been a big week for large meat-eating dinosaur discovery announcements. Two massive predatory dinosaurs have been unearthed, in Egypt and the Isle of Wight, expanding the list of known two-legged carnivorous dinosaurs, or theropods.
Palaeontologists from the University of Southampton, UK, have identified the remains of what they believe to be one of Europe’s largest ever land predators. Their findings are published in the PeerJ Life & Environment journal.
Dug up on the Isle of Wight, off England’s south coast, the animal belonged to spinosaurids – two-legged crocodile-faced dinosaurs. Famous spinosaurids include England’s own Baryonyx and the massive 15 metre-long Egyptian dinosaur Spinosaurus with its distinctive back sail.
“This was a huge animal, exceeding 10 metres in length, and judging from some of the dimensions, probably represents the largest predatory dinosaur ever found in Europe,” says PhD student Chris Barker, who led the study. “It’s just a shame it’s only known from such scant material.”
Dubbed “White Rock spinosaurid” after the geological layer in which it was found, the fossils include large pelvic and tail vertebrae. “Unusually, this specimen eroded out of the Vectis Formation, which is notoriously poor in dinosaur fossils,” says corresponding author Neil Gostling. “It’s likely to be the youngest spinosaur material yet known from the UK.”
The Vectis Formation preserves a 125 million-year-old ecosystem. “White Rock spinosaurid” would have stalked early Cretaceous lagoonal waters and sandflats in a time when Earth’s sea levels began rising.
“Because it’s only known from fragments at the moment, we haven’t given it a formal scientific name,” says co-author Darren Naish. “We hope that additional remains will turn up in time. This new animal bolsters our previous argument – published last year – that spinosaurid dinosaurs originated and diversified in western Europe before becoming more widespread.”
Marks on the bone also showed how the dead body of the giant likely supported a range of scavengers and decomposers.
“Most of these amazing fossils were found by Nick Chase, one of Britain’s most skilled dinosaur hunters, who sadly died just before the COVID epidemic,” says co-author Jeremy Lockwood, a PhD student at the UK’s University of Portsmouth. “I was searching for remains of this dinosaur with Nick and found a lump of pelvis with tunnels bored into it, each about the size of my index finger. We think they were caused by bone-eating larvae of a type of scavenging beetle. It’s an interesting thought that this giant killer wound up becoming a meal for a host of giant insects.”
The researchers hope to determine the spinosaurid’s growth rate and age by generating thin sections of the fossil to look at the microscopic internal properties of the bones.
More on dinosaurs: Were dinosaurs warm- or cold-blooded?
White Rock spinosaurid’s colossal cousin, Spinosaurus aegyptiacus, was discovered in the early 20th century in the Bahariya Oasis in Egypt’s Western Desert. While the original fossils of the sail-backed fish-eater were destroyed in World War II, the scant remains of the animal have sparked imaginations and debates ever since. The site is also home to one of the largest land animals ever, the long-necked herbivorous sauropod Paralatitan.
Now, US and Egyptian researchers have published in Royal Society Open Science their discovery of a smaller predatory dinosaur that would have lived alongside Spinosaurus.
Found in the same celebrated fossil site in the Sahara Desert, the bones were unearthed in 2016 from the 98 million-year-old Bahariya Formation, placing the dinosaur in the middle Cretaceous.
“This bone is just the first of many important new dinosaur fossils from the Bahariya Oasis,” says Sanaa El-Sayed, who co-led the 2016 expedition.
The new dinosaur is a still unnamed species of abelisaurid – the first found in Bahariya Formation. Abelisaurids are short-faced meat eaters with small teeth, stocky hind limbs, and likely vestigial forelimbs. Commonly found in Europe and southern hemisphere continents, the most famous of the group is the demonic-looking Carnotaurus, which has distinctive horns on each brow.
Identified by a well-preserved neck vertebra, the new abelisaurid would have been roughly six metres long. Despite the single vertebra being found, it is virtually identical to vertebrae found from other abelisaurids, making it easy to identify the new creature as a member of the group.
Along with Spinosaurus, the 13 metre-long Carcharodontosaurus and the 11 metre-long Bahariasaurus, the new abelisaurid fossil adds yet another species to the cadre of large predatory dinosaurs that roamed what is now the Egyptian Sahara in the middle Cretaceous. The area was also home to giant crocodiles.
“During the mid-Cretaceous, the Bahariya Oasis would’ve been one of the most terrifying places on the planet,” says study leader Belal Salem, from Ohio University in the US. “How all these huge predators managed to coexist remains a mystery, though it’s probably related to their having eaten different things, their having adapted to hunt different prey.”
The researchers believe the new find has implications for the biodiversity of Cretaceous dinosaurs in Egypt and the entirety of northern Africa. It is the oldest known fossil of Abelisauridae from north-eastern Africa, and shows that, during the mid-Cretaceous, these carnivorous dinosaurs ranged across much of the northern part of the continent, east to west, from present day Egypt to Morocco, to as far south as Niger and potentially beyond.
“In terms of Egyptian dinosaurs, we’ve really just scratched the surface,” notes study co-author Hesham Sallam. “Who knows what else might be out there?”
Recently, Professor Sallam and others have ensured students from Egypt play lead roles in the research process. Both the field expedition that uncovered the new abelisaurid and the follow-up laboratory work were led by students and contributing authors on the paper from the Mansoura University Vertebrate Palaeontology Centre (MUVP) in Mansoura, Egypt. “Working with MUVP and its faculty and students, like Belal Salem, continues to inspire me, as I see the next generation of palaeontologists taking a prominent role in sharing their views on the history of our planet,” says team member and Ohio University biomedical sciences professor Patrick O’Connor.