Two toothy, carnivorous dinosaurs with crocodile-like skulls once stalked the shores of England’s Isle of Wight, new fossils reveal.
Scientists have given the creatures scientific names that translate to “crocodile-faced horned hell heron” and “bank hunter”. Predators are the earliest species of spinosaurids, parents of the odd, possibly amphibious Spinosaurus, which was greater than Tyrannosaurus Rex and had a large sail on the back.
Both new species sported an elongated crocodile-like skull, much like Spinosaurus, but there is no evidence of similar sails. Ceratosuchops inferodios, the newly discovered “hell heron” is known only by a few skull fragments, while the “bank hunter” Riparovenator milnerae, named in honor of the British paleontologist Angela Milner, is known from pieces of skull and coccyx. Previously, only one type of spinosaurid had been found in the UK: an impressive claw hunter known as the Baryonyx.
âWe have known for twenty years that Baryonyx-Dinosaur-like dinosaurs were waiting to be discovered on the Isle of Wight, but finding the remains of two of these animals in close succession was a huge surprise, âsaid study co-author Darren Naish, an independent British paleontologist, said in a press release. Naish also wrote about the results on his blog, Tet Zoo.
Diversity of predators
Although the two new species are only known from a few bones, the bone fragments discovered were very revealing, as they included the skull and teeth of the dinosaurs. The skull contains many anatomical clues to identify different species, including the placement of nerves and muscle attachments. C. inferodios sported a bumpy forehead with low horns and humps.
“We found that the skulls differed not only from Baryonyx, but also each other, suggesting that the UK was home to a greater diversity of spinosaurids than previously thought, “said Chris Barker, a doctoral student at the University of Southampton and lead author of the study, in the press release.
The two new species lived about 125 million years ago, at the beginning Cretaceous period – about 25 million years earlier than the dramatic Spinosaurus. They probably stalked the streams of an ancient floodplain, acting a bit like very large, toothy herons. They likely capture terrestrial fish and prey using their jaws, which are well suited to this style of hunting. Both species were likely to reach around 9 meters in length, depending on the size of their skulls (3.3 feet or 1 m). The different skull shapes of the two species suggest that they might have had slightly different hunting styles, which may have allowed Baryonyx, C. inferodios, and R. milnerae to find food in abundance in a shared landscape.
âIt might seem strange to have two similar and closely related carnivores in an ecosystem, but it’s actually very common for dinosaurs and many living ecosystems,â study co-author David Hone, senior lecturer and director of biological sciences programs at Queen Mary University of London, said in the statement.
Family tree of spinosaurids
The history and development of the spinosaurid family is somewhat controversial; in fact, researchers don’t even agree on whether the late Cretaceous Spinosaurus waded like a heron or swam like a crocodile. But the new discovery suggests that this group of dinosaurs may have first evolved in what is now Europe before spreading to Asia and the supercontinent Gondwana, which then split into Africa. and South America, the researchers wrote in the journal Wednesday (September 29). Nature Communication.
Researchers attempted to build a family tree that places the new spinosaurids in a separate branch (baryonychines, for taxonomy enthusiasts) that separates from the branch that gave rise to Spinosaurus (spinosaurins) about 145 million years ago.
“There is still a lot to learn – the almost total absence of Jurassic spinosaurid taxa [groups] remains a problem! – but, for now, it looks like the group originated in Europe, then spread to Asia and Africa, âNaish wrote on the Tet Zoo. âThe presence of both baryonychines and spinosaurins in Africa indicates distinct migration events for these clades.
Researchers are currently working on a more detailed article on R. milneraethe tail, Naish wrote. The tail bones suggest a high, flat tail, similar to the shape seen on modern caimens. They also plan to further explore the relationships between the different parents of spinosaurids around the world.
Originally posted on Live Science.