Two new species of large predatory dinosaur have been discovered.
Palaeontologists at the University of Southampton confirmed the remains, found by fossil hunters on an Isle-of-Wight beach over several years, belonged to previously unknown species.
The carnivorous dinosaurs are thought to have been 9m (29ft) in length – about the same length as a Stegosaurus – with 1m-long (3ft) skulls like crocodiles.
Researchers believe they roamed the south coast 125 million years ago.
One has been described as a “hell heron”, with scientists describing its hunting style like a fearsome version of the modern-day bird.
One expert hailed the discovery of the two specimens in quick succession as a “huge surprise”, but said palaeontologists had suspected for decades that the remains of such dinosaurs could be found on the island.
The haul of bones was discovered on the beach near Brighstone over a period of several years, and scientists now say they relate to two new species of spinosaurid, a group of predatory theropod dinosaurs closely related to the giant Spinosaurus.
In all, more than 50 bones from the site have been uncovered from rocks that form part of the Wessex Formation, laid down more than 125 million years ago during the Early Cretaceous period.
Dr Neil J Gostling of the University of Southampton, who supervised the project, said: “This work has brought together universities, the Dinosaur Isle museum and the public to reveal these amazing dinosaurs and the incredibly diverse ecology of the south coast of England 125 million years ago.”
Most other finds since have been restricted to isolated teeth and single bones.
Chris Barker, a PhD student at the University of Southampton and lead author of the study, said: “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.”
The first specimen has been named Ceratosuchops inferodios, which translates as the “horned crocodile-faced hell heron”.
With a series of low horns and bumps ornamenting the brow region, the name also refers to the predator’s likely hunting style, which would be similar to that of a heron.
Herons famously catch aquatic prey around the margins of waterways, but their diet is far more flexible than is generally appreciated and can include terrestrial prey too.
The second was named Riparovenator milnerae, which translates as “Milner’s riverbank hunter”, in honour of esteemed British palaeontologist Angela Milner, who died recently.
Dr Milner had previously studied and named Baryonyx – a major palaeontological event whose discovery substantially improved our understanding of these distinctive predators.
The Early Cretaceous rocks on the Isle-of-Wight describe an ancient floodplain environment bathed in a Mediterranean-like climate.
Whilst generally balmy, forest fires occasionally ravaged the landscape, and the remains of burnt wood can be seen throughout the cliffs today.
With a large river and other bodies of water attracting dinosaurs and housing various fish, sharks and crocodiles, the habitat will have provided the newly discovered spinosaurids with plenty of hunting opportunities.
Fossil collectors initially found parts of two skulls before a team from the island’s Dinosaur Isle Museum uncovered a large section of a tail.
The study also suggested how spinosaurids might have first evolved in Europe, before dispersing into Asia, Africa and South America.
Curator Dr Martin Munt said the finds cemented the Isle-of-Wight’s status as one of the top locations for dinosaur remains in Europe.
▪️The collection of about 50 bones will go on display at the Dinosaur Isle Museum in Sandown.