A research team led by the NOVA School of Science and Technology in Portugal has recently redescribed the fossils of a large theropod dinosaur with a crocodile-like skull and spiny back discovered in 1999 around 30 miles south of Lisbon. The remains were initially assigned to Baryonyx walkeri, a genus of theropod dinosaurs that lived in the Early Cretaceous period (130-125 million years ago).
However, new materials recovered in 2020 together with fresh phylogenetic analyses have revealed that the fossils actually belong to a new genus and species, Iberospinus natarioi – a type of spinosaurid that roamed most of the Earth from the Early to Mid-Cretaceous.
It was about 33 feet long and weighed over three tonnes. The new species belonged to a group known as spinosaurs – the largest carnivorous dinosaurs.
Prof Octavio Mateus, of the NOVA School of Science and Technology, Caparica, said: ‘Spinosaurs are some of the most enigmatic theropod dinosaurs due to their unique adaptations to aquatic environments and their relative scarcity.
‘Their diet mainly included fish, although other food items, such as pterosaurs, were consumed.’
One of the most striking features of this dinosaur is its unique pattern of nearly constant teeth replacement, with new teeth growing in its jaws always ready to replace those used or damaged as a result of hunting. Among the fossils discovered near Lisbon, scientists found tooth sockets with two replacement teeth in development next to the one in use.
Although frequent teeth replacement is known to be quite common among spinosaurids, Iberospinus natarioi seemed to have a much quicker turnaround time than its relatives.
Spinosaur teeth have been found inside the fossilised bones of the legendary flying reptiles. They are not as well-known as other meat eating theropods – which include T rex.
This is due to a combination of the fragmentary nature of their fossil record, mainly based on isolated teeth, and their unusual body plan.
Prof Mateus said: ‘This is related with their ecology, particularly linked to aquatic environments, either as specialised pursuit aquatic predators in some cases or as wading-ambush hunters, like herons.’
The creature has been named Iberospinus naturoioi.
In the Jurassic Park 3 movie, a spinosaur controversially killed a T Rex by snapping its neck. But scientists ridiculed the scene, saying the ‘king of the dinosaurs’ was too strong.
However, Iberospinus was still terrifying. Its remarkably preserved remains included razor sharp teeth and skull bones. They were dug up at a famous dinosaur graveyard 30 miles south of Lisbon.
Prof Mateus said: ‘It is one of the most complete spinosaurid specimens in the world.
‘The addition of yet another taxon to the diversity of spinosaurids in Iberia indicates the clade possibly originated in Western Europe.
Although the recovered remains are fragmentary, enough remained to digitally reconstruct the animal in 3D.
Prof Mateus added: ‘Spinosaurids are some of the most enigmatic theropod dinosaurs due to their unique adaptations to aquatic environments and their relative scarcity.’
Iberospinus, decribed in the scientific journal PLOS ONE, was a medium sized spinosaur. Some were up to 50 feet long – and weighed six tonnes.
First discovered by palaeontologists in 1915, they could swim – but mainly hunted on the shoreline and river banks for animals and fish.