Matthew Dempsey
The Ajkaceratops dinosaur turned out to be a ceratopsid after all, following suggestions that it could be a rhabdodontid.
Ceratopsids, the closest relatives of Triceratops, had never been found in Europe – until now.
Fossils of ceratopsid dinosaurs, the group that includes Triceratops and its relatives, are widely distributed throughout the Northern Hemisphere. However, they are curiously absent from Europe.
New research reveals that these missing ceratopsids may have been under our noses all the time, completely reshaping our understanding of European dinosaurs, explains the (NHM).
Since the first dinosaur was identified more than 200 years ago, only four potential ceratopsids have been unearthed across Europe. However, the fragmentary nature of these fossils meant that your true identity had remained the subject of controversy.
Instead, scientists thought that Europe was dominated by a group of little-known dinosaurs called rhabdodontids. These animals, which are relatives of iguanodonsare not found anywhere else on Earth.
A new one, published this Wednesday in Nature, now explain why. After studying an 84 million year old dinosaur called Ajkaceratopsa team of NHM paleontologists realized that many rhabdodontids may actually be misidentified ceratopsids.
These dinosaurs lived in Europe when the continent was made up of a series of islands scattered across the Tethys Seawhich may help explain your unique diversity.
The teacher Susannah Maidmentthe NHM dinosaur expert who led the paper, says the discovery rewrites what paleontologists know over Cretaceous Europe.
“Our study shows that, rather than being completely absent, ceratopsids were actually quite common in Europe“, says Maidment. “This means that European dinosaur faunas were probably not that different from other parts of the northern hemisphere.”
“In this case, the idea that Europe’s islands drove the evolution of many unique species may not be as strong as thought. This makes it even more important to re-examine European dinosaur fossils to discover what was happening here in the Late Cretaceous”, adds the researcher.
Analysis of fossil ajkaceratops skulls has finally provided proof that ceratopsids finally arrived in Europe.
The study authors also discovered that not only was this dinosaur definitely a ceratopsidas well as a closely related rhabdodontid called mochlodontewas actually the same species.
By confirming the existence of ceratopsids in Europe, the study fills a long-existing gap in journey these dinosaurs took across the northern hemisphere.
The first ceratopsids evolved in Asia before dispersing several times across North America, where evolved into large, frilly speciessuch as Triceratops and Torosaurus.
A easiest route These dinosaurs could have followed would have been through Europe, but the historic lack of fossils from this region challenged this narrative.
“We know that dinosaurs could cross the Atlantic, which was just begin to open during the Cretaceous“, explains Maidment. “Specimens of allosaurus were found in Portugal and the USAshowing that they had at least some ability to move between continents“.
“Many animals can swim and since the islands in the central European basin weren’t that far apart, it would make sense that dinosaurs were able to jump from island to island. It would be much stranger if they couldn’t”, notes the researcher.
“Although Iguanodon and Triceratops look very different, the groups they are part of evolved from a common ancestor, meaning they both inherited certain characteristics“, explains Maidment. “They also independently developed quadrupedalism, complex chewing mechanisms and a large body size”.
“This means that their teeth and limbs look quite similar, both because of their shared history and their way of life. So when we only have small parts of the skeleton to observeit can be quite difficult to distinguish what is what.”
Maidment hopes the results of the new study will encourage paleontologists to revisit existing dinosaur species and to re-examine what they think they know.
“We cannot assume that a species’ identity is correct just because it has been studied. Our study demonstrates how museum collections are not just storage: are a living archive which needs constant updating”, concludes the researcher.
