A newly published scientific paper has described the fragmentary remains of a super-sized theropod dinosaur unearthed on the Isle of Wight. With an estimated length exceeding 10 metres, the fossils could represent the largest carnivorous dinosaur found in Europe.

The fragmentary nature of the fossilised bones means that a more precise identification and the establishment of a new genus is not currently possible, although the fossils do probably represent a new taxon.

Europe’s Largest Land Predator – A Member of the Spinosauridae

Based on anatomical traits identified from these weathered and damaged bones (they may have been trampled by other dinosaurs), the researchers are not able at this time to assign this specimen to a specific branch of the spinosaurid family tree, instead the material is classified at the family level of taxonomy and assigned to the Spinosauridae.

Commenting on the significance of this discovery, PhD student and lead author of the scientific paper Chris Barker (University of Southampton) stated:

“This was a huge animal, exceeding ten metres in length and probably several tonnes in weight. Judging from some of the dimensions, it appears to represent one of the largest predatory dinosaur ever found in Europe – maybe even the biggest yet known. It’s a shame it’s only known from a small amount of material, but these are enough to show it was an immense creature.”

Not “Europe’s Largest Ever Land Dinosaur”

Although massive and the largest theropod currently known from the Wealden Supergroup and based on bone measurements, potentially the largest theropod dinosaur found in Europe to date, Everything Dinosaur team members have noted inaccuracies in news articles. Some media outlets have declared that these fossils represent “Europe’s largest ever land dinosaur”. This is not true, fossils assigned to the Sauropoda, including several specimens from the Isle of Wight indicate, that there were many, much larger dinosaurs present in the Early Cretaceous of Europe when spinosaurids roamed.

The “White Rock Spinosaurid”

Nicknamed the “White Rock spinosaurid” after the geological layer in which it was found (the basal unit [the White Rock Sandstone equivalent] of the Vectis Formation near Compton Chine, on the southwest coast of the Isle of Wight), the fossils are around 125 million years of age (Barremian stage of the Lower Cretaceous).

It represents the first documented spinosaurid from the Vectis Formation of the Isle of Wight, extending the temporal span of the clade in the British fossil record to the late Barremian.

Dr Neil Gostling (University of Southampton), commented:

“Unusually, this specimen eroded out of the Vectis Formation, which is notoriously poor in dinosaur fossils. It’s likely to be the youngest spinosaur material yet known from the UK.”

Dinosaur remains are generally very rarely found in the Vectis Formation, although these deposits represent sandflats and lagoonal environments where dinosaurs roamed and spinosaurid fossils have been found in other strata laid down in similar palaeoenvironments.

Vertebrate palaeontologist and co-author of the scientific paper Darren Naish commented:

“Because it’s only known from fragments at the moment, we haven’t given it a formal scientific name. 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.”

The researchers hope to cut thin sections in some of the fossil remains to look at the microscopic internal properties of the bones. This may provide information about the growth rate of this dinosaur, its age and maturity.

Marks on the bone also showed how, even after death, the body of this giant probably supported a range of scavengers and decomposers.

Co-author and PhD student Jeremy Lockwood (University of Portsmouth and the London Natural History Museum), added:

“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. 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 insects.”

The Youngest Spinosaurid Known from the UK

The fossils also represent the youngest spinosaurid known from the UK and it is most likely a new taxon but a lack of convincing autapomorphies in the fossil material found to date has prevented a more precise taxonomic classification.

Southampton University researchers were prominent in a 2021 study that described two other spinosaurs Riparovenator milnerae and Ceratosuchops inferodios, from the Isle of Wight. Both these dinosaurs come from the older Wessex Formation that underlies the Vectis Formation, so they would have been alive several million years before the “White Rock spinosaurid” evolved.

To read about R. milnerae and C. inferodios: Two New Spinosaurids from the Isle of Wight.

Everything Dinosaur acknowledges the assistance of a media release from the University of Southampton in the compilation of this article.

The scientific paper: “A European giant: a large spinosaurid (Dinosauria: Theropoda) from the Vectis Formation (Wealden Group, Early Cretaceous)” by Chris T. Barker, Jeremy A. F. Lockwood, Darren Naish, Sophie Brown, Amy Hart, Ethan Tulloch and Neil J. Gostling published in PeerJ.

The recently aired television documentary series “Prehistoric Planet” depicted giant azhdarchid pterosaurs such as Quetzalcoatlus and Hatzegopteryx as competent aeronauts extremely proficient at flight and capable of travelling huge distances without ever having the need to land. This idea has been challenged in newly published research that suggests Quetzalcoatlus was more suited to short-range flights.

The Largest Known Flying Animals

A number of vertebrates are volant (capable of powered flight). Amongst this diverse and eclectic group consisting of bats, birds and pterosaurs are some giants. For example, Pelagornis sandersi*, a pelagornithid bird from the Late Oligocene of Southern Carolina had an estimated wingspan of about 7 metres. Argentavis magnificens was an enormous condor from the Late Miocene of Argentina. It had a wingspan in excess of 6 metres and it was very much larger than its extant, distant relative the California condor (Gymnogyps californianus).

During the Late Cretaceous enormous pterosaurs dominated the skies. Pteranodon was thought to be one of the biggest, but over the last fifty years or so, evidence has emerged of the Azhdarchidae – a family of Late Cretaceous flying reptiles, some members of which such as Hatzegopteryx, Quetzalcoatlus, Arambourgiania and the recently described Thanatosdrakon* were the largest flying animals known to science.

Comparing Today’s Large Birds with Ancient Flyers

A new study, led by Dr Yusuke Goto from Nagoya University (Japan), along with researchers from the Centre d’Etudes Biologiques de Chizé (France) and the University of Tokyo (Japan), calculated and compared the ability of some of these ancient flyers to the capabilities of large, extant birds such as the Wandering albatross (Diomedea exulans), the California condor, the Magnificent frigatebird (Fregata magnificens) and the Kori bustard (Ardeotis kori). The Kori bustard has a bodyweight in the region of 10-18 kilograms, it is the heaviest flying bird alive today.

The team set out to quantify the soaring performance of these animals using a combination of potential speed of flight, soaring efficiency and the wind speed and conditions required to sustain aerial activity.

They analysed two types of soaring behaviour:

• Thermal soaring – which uses updrafts arising from the land or ocean to ascend and glide. A method of flight observed in eagles and frigatebirds.
• Dynamic soaring – which uses wind gradients over the ocean, as demonstrated by albatrosses and petrels.

The Soaring Abilities of Pteranodon

The scientists concluded that Pteranodon, fossils of which are associated with marine environments, was probably an ocean dweller, excelling at soaring flight using updrafts over the sea. The predicted flying style of Pteranodon was similar to that seen in extant, ocean-going frigatebirds.

Challenging Perceptions About Quetzalcoatlus

This analysis challenges perceptions about the flight capabilities of Quetzalcoatlus. The team concluded that this azhdarchid was not well adapted for soaring flight, even when wind speeds and atmospheric conditions were favourable.

Previous studies had proposed that Quetzalcoatlus was capable of travelling hundreds if not thousands of miles without having the need to land, this study showed that its thermal soaring abilities were much lower than that seen in living birds.

The idea that large azhdarchids were terrestrial hunters has been proposed previously, but the research team go further suggesting that Quetzalcoatlus and other giants were short-range flyers and did spend most of their time on land. The Kori bustard is proposed as a modern-day analogue for the biggest members of the Azhdarchidae. It is largely terrestrial and only flies relatively short distances.

The research team’s results corroborated the findings of previous studies examining the flying abilities of Argentavis magnificens. They found that it was well suited to thermal soaring. In contrast, the team found that Pelagornis sandersi was better suited to thermal soaring, although earlier studies had proposed dynamic soaring.

To read Everything Dinosaur’s article from 2014 about the discovery of P. sandersi: The Largest Ever Flying Bird Pelagornis sandersi.

Everything Dinosaur’s recent article (May 2022), on Thanatosdrakon: The Dragon of Death.

The scientific paper: “How did extinct giant birds and pterosaurs fly? A comprehensive modeling approach to evaluate soaring performance” by Yusuke Goto, Ken Yoda, Henri Weimerskirch and Katsufumi Sato published in the PNAS Nexus.