A “hell heron” – described as a fearsome reptile with a hunting style like the modern-day bird – is one of two new species of dinosaur discovered in the UK, scientists announced on Wednesday.
The carnivores roamed what is now the Isle of Wight, off the south coast of England, 125 million years ago.
They are thought to have been about nine metres long with crocodile-like skulls.
The discovery comes after scientists found remains of one of the largest new dinosaur species in Australia, in June.
One expert hailed the discovery of the two Isle of Wight specimens in quick succession as a “huge surprise”, but said palaeontologists had suspected for decades that such fossils could be found on the island.
The haul of bones was discovered on the beach near the village of Brighstone over a period of several years.
Scientists say they relate to two new species of Spinosaurid, a group of predatory theropods – dinosaurs characterised by hollow bones and three-toed feet.
The family includes the giant Spinosaurus – which may have reached 18m in length.
More than 50 bones from the site have been uncovered from rocks that form part of the Wessex Formation – fossil-rich English geological formation – laid down more than 125 million years ago during the Early Cretaceous period.
“This work has brought together universities, the Dinosaur Isle museum [in the Isle of Wight] and the public to reveal these amazing dinosaurs and the incredibly diverse ecology of the south coast of England 125 million years ago,” said Dr Neil J Gostling of the University of Southampton, who supervised the project.
The only Spinosaurid skeleton previously unearthed in the UK belonged to a different branch of the family, Baryonyx. That was discovered in 1983 in Surrey, south-east England.
Most other finds since have been restricted to isolated teeth and single bones.
Analysis of the Isle of Wight bones carried out at the University of Southampton and published in peer-review journal Scientific Reports suggested they belonged to species of dinosaurs previously unknown to science.
“We found the skulls to differ not only from Baryonyx but also one another, suggesting the UK housed a greater diversity of Spinosaurids than previously thought,” said Chris Barker, a PhD student at the University of Southampton and lead author of the study.
Co-author Darren Naish, an expert in British theropod dinosaurs, said the discovery of Spinosaurid dinosaurs on the Isle of Wight was a long time coming.
“We've known for a couple of decades now that Baryonyx-like dinosaurs awaited discovered on the Isle of Wight, but finding the remains of two such animals in close succession was a huge surprise.”
Heron a hellish sight
The first specimen has been named Ceratosuchops inferodios, which translates as the “horned crocodile-faced hell heron".
While the animal had series of low horns and bumps ornamenting the brow region, the name also refers to its likely hunting style, which would have been similar to that of a heron, said researchers.
Herons usually hunt around the margins of waterways, standing completely still before stabbing their prey – often fish or amphibians – with their long, sharp beak.
The second was named Riparovenator milnerae, which translates as “Milner's riverbank hunter”, in honour of esteemed British palaeontologist Dr Angela Milner, who died recently.
Dr Milner had previously studied and named Baryonyx, improving understanding of these predators.
The Early Cretaceous rocks on the Isle of Wight reveal evidence of an ancient floodplain environment with a Mediterranean-like climate.
While generally balmy, forest fires occasionally ravaged the landscape, and the fossilised remains of burnt wood can be seen throughout the cliffs today.
With a large river and other bodies of water, the habitat would have provided the newly discovered Spinosaurids with plenty of hunting opportunities.
The fossils will go on display at Dinosaur Isle Museum, at Sandown in the Isle of Wight.