Traces of the ancestor of the world's oldest mammals discovered in Mallorca

PalmA research team has discovered in Banyalbufar a type of fossilized footprint, previously unknown to science, attributed to a gorgonopsis, the oldest mammalian ancestor in the world. This group of saber-toothed predators from the Permian region is related to the ancestors of mammals. The footprints, dating back between 270 and 280 million years, were found very close to skeletal remains of this animal and have allowed the reconstruction of its gait, which is closer to that of mammals than reptiles.

The discovery, which has been published in several scientific journals, is exceptional, not only because of the number of fossil remains found, but also because it is the oldest gorgonopsis on the planet, the predecessor of saber-toothed cats that would eventually give rise to mammals.

Gorgonopsis are an extinct group of synapsids that lived during the Permian Period, between 270 and 250 million years ago. They belong to the evolutionary line that would give rise to the first mammals 50 million years later. They were warm-blooded animals, like today's mammals, but, unlike most mammals, they laid eggs.

They were carnivores and the first animals to develop the characteristic saber-toothed teeth. They were often the apex predators of the ecosystems in which they lived and would have appeared similar to a dog, but without ears or fur. The remains recovered in Mallorca belong to a small-medium sized animal, approximately one meter long, and come from a site located in Banyalbufar. It was excavated in three separate campaigns, during which a large amount of material was recovered.

"The large number of bone remains is surprising. We have found everything from skull fragments, vertebrae, ribs, and even a very well-preserved femur. Honestly, when we started this excavation, we never thought we would find so many remains of an animal," said Professor of Natural Sciences (MUCBO | MBCN), associate researcher at ICP-BUSCA, and first author of the article.

In recent years, Mallorca has provided exceptional fossil remains from the Permian period. Of note are the finds of the Tramuntasaur, a new species of reptile described in 2023, and, more recently, the discovery of a partial skeleton of a Gorgonopsis, the oldest known therapsid in the world to date. Its location in the Balearic Islands is somewhat unusual, as the known remains of Gorgonopsis until now belonged to very high latitudes, such as Russia and South Africa.

Its age also surprised the researchers who conducted the study. "It is very likely the oldest Gorgonopsis on the planet. What we found in Mallorca is at least 270 million years old, and the other records of this group worldwide are mostly much younger," comments Josep Fortuny, senior author of the article and head of the Institute's Computational Biomechanics and Life History Evolution (ICP-BÚSQUEDA) group.

Among the excavated fossil remains, a nearly complete leg stands out, allowing them to study how the animal moved. Unlike reptiles, which have a more ancestral locomotion with legs further apart, the gorgonopsis had legs arranged more vertically and, therefore, moved in a way that would be halfway between that of reptiles and that of mammals. This system is more efficient for walking and, especially, for running.