Oldest ancestor of a mammal discovered in Mallorca

An international research team led by the Institut Català de Paleontologia Miquel Crusafont (ICP) and the Museu Balear de Ciències Naturals (MUCBO | MBCN) has described a fossil animal that lived between 270 and 280 million years ago in the present-day Majorca.

The discovery is exceptional, not only because of the number of fossil remains found, but also because it is the oldest known gorgonopsian on the planet, the lineage of saber-toothed predators that would eventually give rise to mammals . The research was published in the journal Natural communications.

Gorgonopsians are an extinct group of synapsids that lived in the Permian, between 270 and 250 million years ago. They belong to the evolutionary lineage which gave birth to the first mammals 50 million years later.

They were warm-blooded animals like modern mammals, but unlike most of them, they laid eggs. They were carnivorous and were the first animals to develop the characteristic saber teeth. They were often the apex predators of the ecosystems in which they lived, and their appearance was similar to that of a dog, but without ears or fur.

The remains recovered in Mallorca belong to a small to medium-sized animal, measuring approximately one meter long, and come from a site located in the municipality of Banyalbufar (Serra de Tramuntana, Mallorca). The excavations were carried out during three different campaigns during which a large quantity of materials were recovered.

“The large number of skeletal remains is surprising. We found everything from fragments of skull, vertebrae and ribs to a very well preserved femur. In fact, when we started this excavation, we would never have thought to find so many remains of bones of an animal of this type in Mallorca”, explains Rafel Matamales, curator of the Museu Balear de Ciències Naturals (MUCBO | MBCN), associate researcher at the ICP and first author. of the article.

Its location in the Balearic Islands is in itself an unusual fact. The known remains of gorgonopsians before this discovery belonged to very high latitudes such as Russia or South Africa. Its age also surprised the researchers who conducted the study.

“This is probably the oldest gorgonopsian on the planet. The one we found in Mallorca is at least 270 million years old, and other records of this group around the world are, at least, slightly more recent “, underlines Josep Fortuny, lead author of the article and head of the Computational Biomechanics and Evolution of Life History group at the Institut Català de Paleontologia Miquel Crusafont (ICP).

Among the fossil remains unearthed, an almost complete leg stands out, which allowed researchers to study how the animal moved. Unlike reptiles, which have a more ancestral locomotion with their legs further apart, gorgonopsians had their legs more vertical and therefore moved in an intermediate manner between reptiles and mammals. This system is more effective for walking and especially for running.

The saber teeth recovered confirm his diet. “We know that this is a carnivorous animal, a trait shared by all gorgonopsians around the world. Saber teeth are a common feature among large predators in ecosystems, and what we found was likely one. one in the environment in which he lived”, emphasizes Àngel. Galobart, researcher at the ICP and director of the Museu de la Conca Dellà.

When Majorca was not an island

During the Permian period, around 270 million years ago, Majorca was not an island but part of the supercontinent Pangea. It was located at an equatorial latitude, where countries like Congo or Guinea are located today. The climate was monsoon, alternating between wet and very dry seasons.

The site where the fossils were found was found to be a floodplain with temporary ponds where gorgonopsians and other animals drank. Among the animals that cohabited in this ecosystem were the moradisaurine captorhinids, an ancient group of herbivorous reptiles to which Tramuntanasaurus tiai belongs, which may have been part of the gorgonopsians’ diet.

Despite the small area they occupy, the Balearic Islands have an exceptional fossil heritage. The most studied and best known fossils come from the Pleistocene and Holocene.

However, the fossil record from other periods is considerably less known. Nevertheless, remarkable fossils have been discovered, such as the world’s oldest mosquito, nearly a thousand species of ammonoids (cephalopods related to squid), ancestors of horses and hippos, giant sharks and large coral reefs. .