They discover on an island a species of fossil reptile hitherto unknown

Researchers have scientifically described the new species of reptile Tramuntanasaurus tiai from a very well-preserved fossil skeleton found in rocks from Mallorca (one of the Balearic Islands, in Spain) dating back about 270 million years.

The work has been carried out by specialists from the Balearic Museum of Natural Sciences (MUCBO) and the Catalan Institute of Paleontology Miquel Crusafont (ICP).

The new species of reptile is a moradisaurine captorrhinid, a group of herbivorous reptiles that lived only during the Permian, between 299 and 251 million years ago, and have no current representatives. Within this group, Tramuntanasaurus tiai was a medium-sized species, approximately 50 centimeters in length from head to tail. Other species in this group reached 2 meters in length. Moradisaurine captorhinids are one of the best-known herbivorous tetrapods from the Permian, but most of what is known about them is based solely on skulls that have been found around the world. They lived in equatorial and tropical latitudes. Possibly they tolerated occasional arid conditions better than other herbivores.

The fossil remains that have made it possible to describe the new species were found in Banyalbufar (Serra de Tramuntana, Mallorca) and are extraordinarily well preserved. “The animal is almost complete, with the different bones in anatomical position, which is quite exceptional in the fossil record of this period,” explains Rafel Matamales, curator at the Balearic Museum of Natural Sciences (MUCBO) and co-author of the study. As in the rest of moradisaurines, several rows of teeth can be seen in the jaw. “We have verified that the tramuntanasaurs had five rows of teeth in the lower and upper jaws. This allowed them to chew and break up the plant matter they fed on before ingesting it,” explains the researcher.

The scientific name of the new species, “Tramuntanasaurus”, means “the reptile of Tramuntana” and refers to the area where the fossil was found. The specific epithet, “tiai”, is a tribute to Sebastià (Tià) Matamalas, father of paleontologist Rafel Matamales, who discovered the skeleton. “During the field work, my father, who was participating as a volunteer, saw something protruding from the rock and it seemed strange to him. When we removed it, we could see the jaws and other bones of the skeleton,” said the paleontologist.

Recreation of what three typical specimens (one adult in the foreground and two juveniles in the background) of Tramuntanasaurus tiai must have looked like in life between horsetails (equisete) in a Permian floodplain in Majorca. (Illustration: Henry Sutherland Sharpe ©)

During the Permian (approximately 270 million years ago), Majorca was not an island, but was attached to the supercontinent Pangea. This great landmass was crescent-shaped and stretched from the North Pole to the South, grouping almost all the continents on the planet. Specifically, Mallorca was located on its eastern margin, relatively close to the sea, and at an equatorial latitude. “The climate was also quite different from today,” explains Josep Fortuny, head of the Computational Paleobiology research group at the ICP, who has also participated in the research. “The tramuntanasaurs lived in a tropical climate, where dry seasons alternated with very rainy ones,” explains the researcher.

The environments recorded by the rocks of the Permian of Mallorca reflect this climate. The fossil remains were found in an environment that corresponds to a landscape with large meandering rivers with associated floodplains. The remains of the tramuntanasaurus were found precisely in what must have been a temporary pool that possibly acted as a watering hole in the driest seasons and attracted the surrounding fauna. “This explains the concentration of skeletons and footprints found in this area,” says Eudald Mujal, a researcher at the Stuttgart Natural History Museum in Germany, who has also participated in the research. In the same site, two different types of fossil tracks had been found that were suspected to belong to moradisaurine captorhinids. “Since the skeleton preserves the almost complete and articulated left foot, we have been able to compare its anatomy with the footprints and we are quite sure that the smaller ones correspond to the tramuntanasaurus,” says Mujal. In paleontology it is very exceptional to find bones and traces in close levels that allow them to be related.

The description of the new species of reptile T. tiai is one more step in the great task of joint research that the MUCBO research staff has carried out in recent years at sites in Mallorca and Menorca, which has made it possible to reconstruct the fauna and the paleoenvironment of this area of ​​the planet during the Permian. Previous studies had already revealed rich and diverse ecosystems with the presence of a wide variety of vertebrates, invertebrates and plants.

All this wealth of fauna and flora vanished about 250 million years ago, when the most important and devastating extinction in the history of life on Earth occurred, also known as “the great dying”. “Intense volcanic activity altered the planet’s global climate in a geologically short period and caused the extinction of more than 90% of marine species and 70% of terrestrial vertebrates”, explains Àngel Galobart, director of the Conca Dellà Museum and co-author of the study. “This explains why many of the faunas that lived at that time, such as the tramuntanasaurus, do not have current representatives,” says the researcher.

The study is titled “A new medium-sized moradisaurine captorhinid eureptile from the Permian of Mallorca (Balearic Islands, western Mediterranean) and correlation with the co-occurring ichnogenus Hyloidichnus”. And it has been published in the academic journal Papers in Palaeontology. (Source: ICP)