Reconstruction of the possible appearance of Ajkaceratops kozmai. Original artwork by Matthew Dempsey.
Fossils of ceratopsian dinosaurs, the group containing Triceratops and other horned dinosaurs, have been vanishingly rare in Europe while being widespread across Asia and North America, until now.
New research confirms Ajkaceratops is a ceratopsian. This dinosaur would have lived around 84 million years ago in Europe, which at the time was a series of islands dotted around the margins of the Tethys Sea.
A new study published today in the journal Nature reveals that some rhabdodontid dinosaurs, a poorly understood group thought to be relatives of Iguanodon and found only in Europe, are in fact also ceratopsians.
Scientists at London’s Natural History Museum, along with a team of experts from across the UK and Europe, have today solved the puzzle of Europe’s missing horned dinosaurs.
Although widespread in North America and Asia, ceratopsian dinosaurs have previously only been known in Europe by just a handful of poorly preserved, fragmentary and controversial fossils. The recent discovery of new fossils belonging to Ajkaceratops prompted a group of scientists, including Prof Susannah Maidment, palaeontologist at the Museum, to take another look at this species.
Described first in 2010, Ajkaceratops has been controversial, with some considering it to be a horned dinosaur, while others interpreted it to be a relative of Iguanodon but with possible characteristics of a ceratopsian. Using new, more complete cranial material from Ajkaceratops plus CT evidence and multiple analyses of evolutionary relationships, the team found that not only was this dinosaur a ceratopsian, but that a previously described rhabdodontid called Mochlodon was also the same species.
The analyses also showed that some other dinosaurs previously thought to be rhabdodontids had been long misclassified and were also ceratopsians.
“While Iguanodon and Triceratops look very different, the groups they are part of both evolved from a common ancestor, meaning they’ve both inherited certain characteristics,” explains Prof Maidment. “They also independently evolved four-leggedness, 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 way of life. So, when we only have small parts of the skeleton to look at, it can be quite difficult to tell what’s what.”
By confirming the existence of ceratopsians in Europe, the study fills in a long-standing gap in the journey of these dinosaurs across the northern hemisphere.
Prof Richard Butler of the University of Birmingham and co-author on the paper says, “Because the first fossils discovered of Ajkaceratops were so incomplete it meant lots of scientists doubted it was a ceratopsian. What’s so exciting about the new Ajkaceratops fossil is that it allows us to confirm that horned dinosaurs roamed the islands of Cretaceous Europe, but also challenges us to radically rethink our understanding of these ancient ecosystems.”
Across the pond
The earliest ceratopsians, such as Yinlong, evolved in Asia before spreading multiple times into North America, where they evolved into frilled species such as Triceratops and Torosaurus. The easiest route for these dispersals would be through Europe – but the lack of fossils challenged this.
“We know that dinosaurs were able to cross the Atlantic, which was just starting to open during the Cretaceous,” Susannah explains. “Dinosaurs such as Allosaurus have been found in Portugal and the USA, showing that they had at least some ability to move between continents. Lots of animals can swim and, as the islands of the central European basin weren’t that far apart, it would make sense that dinosaurs were able to island hop.”
Prof Steve Brusatte, vertebrate palaeontologist at the University of Edinburgh and co-author on the paper said, “Horned dinosaurs like Triceratops are some of the most iconic dinosaurs but most of them are from North America, and now we've found them in Europe, hiding in plain sight because they've been misidentified for decades as other types of dinosaurs.”
The importance of Museum collections
This study demonstrates the importance of museum collections. By reassessing and reinterpreting the many treasures held in natural history collections using data derived from new discoveries and the latest state-of-the-art techniques, scientists can gain a better understanding of the lives of these animals, their evolution over time, and the history of the planet.
A hidden diversity of ceratopsian dinosaurs in Late Cretaceous Europe is published today in Nature. DOI 10.1038/s41586-025-09897-w.
Evolution of Life is one of the Natural History Museum’s research themes. Determining the causes and consequences of evolutionary and environmental change is central to understanding life on Earth.
ENDS
Natural History Museum Press Office
Tel: +44 (0)20 7942 5654 / 07799690151
Email: press@nhm.ac.uk
Image assets are available here.
About The Natural History Museum
The Natural History Museum is a world-leading scientific research centre and one of the world’s most visited museums. Our mission is to create advocates for the planet – people who act for nature.
Our 400 scientists are finding solutions to the planetary emergency - from reversing biodiversity loss to resourcing the green economy.
We are seeking an additional £150 million to transform our South Kensington building: placing our groundbreaking research at its heart, revitalising four existing galleries, opening two new magnificent galleries and delighting 1 million more visitors a year with the wonders of the natural world.