An international team of palaeontologists has described a new species of amphicyonid, an extinct group of carnivores that combined dog-like and bear-like traits, from a skull discovered three decades ago in Catalonia. The study, published in the Journal of Mammalian Evolution, identifies the specimen as Paludocyon moyasolai, named in honour of palaeontologist Salvador Moyà-Solà.
The fossil was recovered during excavation campaigns in the 1990s at Els Casots, a site in the municipality of Subirats (Alt Penedès), near Barcelona. Over time, Els Casots has become one of the most important Miocene localities in Europe. Initially, researchers assumed the skull belonged to a known species of Paludocyon, based on fragmentary remains from the same area and other countries. The piece was stored away, considered unremarkable.
It was not until 2014, during preparation of a doctoral thesis, that a closer examination revealed discrepancies. The species it had been compared with was far more robust — roughly the size of a lion or tiger, weighing close to 200 kilograms. The skull in storage was smaller and likely less muscular. Over the past two years, the team at the Institut Català de Paleontologia Miquel Crusafont confirmed their suspicion: this was a previously undescribed species.
A Medium-Sized Predator in a Tropical Lagoon
According to the researchers, Paludocyon moyasolai was about the size of a large dog, weighing between 50 and 70 kilograms. The remains include the skull, most of the dentition, and an isolated lower molar. The teeth show unusual development of the posterior molars, with a particularly broad second upper molar and a third larger than typical for the genus. This suggests a varied diet, consistent with a mesocarnivorous hunter capable of chasing small and medium-sized prey — such as primitive deer, bovids, and ancestral pigs — without being the most powerful animal in its environment.
The same site yielded a second, considerably larger amphicyonid species, roughly the size of a leopard, which has yet to be formally described. Around 15.9 million years ago, the area was a shallow lagoon surrounded by tropical forest, home to crocodiles, snakes, fish, and a notable diversity of mammals. The aquatic environment allowed exceptional preservation: bodies became trapped in mud after death, protecting them from decay.
Another Piece in the Map of Miocene Carnivores
This discovery adds to broader research into how communities of large carnivores were organised during the Miocene on the Iberian Peninsula. A previous study, involving the Complutense University of Madrid, examined slightly more recent sites — Los Valles de Fuentidueña in Segovia and Cerro de los Batallones in Madrid — where an unusually high number of carnivore species coexisted: bear-dogs, felids, hyaenas, and bears. Using stable isotope analysis on more than 200 samples of tooth enamel, that study, published in Palaeontology, showed that competition was intense, except for the amphicyonid itself and the primitive hyaena, which hunted different prey in more open habitats.
This isotope work allows reconstruction of diet with considerable precision while barely damaging the fossil: a few milligrams of enamel are removed with a dentist's drill and analysed by mass spectrometry. Applied across different sites and time periods, this approach builds an increasingly detailed picture of how fauna responded to environmental changes — the shift from dense forests to more open, arid landscapes — and what strategies allowed some species to coexist despite intense competition.
Paludocyon moyasolai fits into this story as another piece of the puzzle, slightly earlier in time than the episodes studied at Fuentidueña or Batallones but belonging to the same amphicyonid family that dominated much of Eurasia and North America during the Cenozoic. Each new specimen described helps refine the group's evolutionary tree and understand how it became completely extinct a few million years ago.
The study involved the Institut Català de Paleontologia Miquel Crusafont, the National Museum of Natural Sciences of the CSIC, the University of Valencia, the Autonomous University of Barcelona, the Complutense University of Madrid, Ecuador's National Biodiversity Institute, and the South African museum Iziko. The discovery underscores the importance of long-term curation and re-examination of museum collections, which can yield new insights decades after initial excavation.
