Animal fossils from 240 million years ago found in Poland

Animal fossils from 240 million years ago found in Poland

Polish scientists have discovered the remains of over a thousand specimens of extinct animals from about 240 million years ago. Among them are the bones of a reptile unknown to science so far.

In Miedary near Tarnowskie Góry (Upper Silesia), a team of scientists from the Faculty of Biology of the University of Warsaw and the Institute of Paleobiology of the Polish Academy of Sciences made a unique discovery.

The researchers found layers that contain an unusually large number of animal bones from about 240 million years ago.

“We are conducting excavations in the area of ​​an abandoned excavation of a former brickyard. The layers of red and green mudstones that we are exploring date back to the Middle Triassic. This is an important moment in the history of life on Earth because many groups of animals emerged then, for example mammals, lizards and dinosaurs. In Miedary, in the Zbrosławice commune, this breakthrough moment in the prehistory of our planet is recorded,” said Dr. Łukasz Czepiński from the Institute of Paleobiology of the Polish Academy of Sciences, co-author of the study, at a press conference in Warsaw on Tuesday.

The Silesian discovery is a “world-scale event”, as Dr. Czepiński says. And he explains that sites from the Middle Triassic are very rare. The nearest places with fossils of similar age are hundreds of kilometers away from Miedary.

Scientists from the University of Warsaw and the Polish Academy of Sciences have been working in this place for a decade and have already excavated thousands of bones.

During the Middle Triassic period, the Earth looked completely different than it does today. All landmasses were connected into one supercontinent, Pangea. 

In its eastern part, the Tethys Ocean formed a huge bay. The place that researchers are exploring in Miedary today was located in its southern part. The sea entered and retreated into this vast depression several times, in cycles lasting many thousands of years.

“The animals found in Miedary are buried in marine sediments. The bones are found in layers approximately one meter thick,” explains Wojciech Pawlak from the Faculty of Biology at the University of Warsaw, one of the authors of the publication.

The organisms whose remains were discovered in Silesia include four species of small sharks (including Acrodus and Polycrodus) , some with horns and spines on their fins. In the mudstones, researchers also found fossils of bony fish, including: meter long Saurichthys with a lanceolate body. The site also found bones of a 6-meter-long crocodile-like amphibian, Mastodonsaur, and a fish-eating reptile, Tanystropheus, of a similar size, which had an exceptionally long neck composed of 13 vertebrae. His remains are accumulated in Miedary in quantities found nowhere else in the world.

Dr Mateusz Talanda from the UW’s Faculty of Biology  – one of the discoverers of more than 1,000 bones of extinct animals – also added that “some of them were previously unknown in Poland, and some have not been found anywhere in the world before.

“We have discovered, among others, the remains of the crocodile-like Mastodonsaurus, the fish-eating yet unnamed armoured reptile and the aquatic predator Jaxtasuchus.”

“Based on the species composition of this community, it seems to us that we are dealing with a very special environment, rarely identified in the fossil record. The bay did not have the salinity typical of either freshwater or saltwater reservoirs. In this respect, it was probably similar to today’s Baltic Sea.” – explains Wojciech Pawlak.

In total, scientists from the University of Warsaw and the Polish Academy of Sciences discovered fossils of 24 species of fish, amphibians and reptiles. 

One of the most valuable finds from Miedary are the bones of a mysterious, armored relative of dinosaurs and crocodiles.

“We are still collecting fossils of this animal; there are many indications that they are scattered bones of one individual. We hope that in the coming years we will find more specific remains, for example a skull. However, we already know that this is a new type of reptile that has not been has been found nowhere else in the world,” Dr. Czepiński tells PAP.

“The abundance of bones in these layers is very large, and the remains are perfectly, three-dimensionally preserved. Although the animals discovered there are mostly known to science, the site in Miedary provides material that will allow us to learn about them much better.

Thanks to the unprecedented amount of fossils, we will be able to conduct field work there will continue for many years. Our dream is for these remains to be on permanent exhibitions in Warsaw and Miedary,” says Pawlak. (PAP)

Research is published in the “Journal of Vertebrate Paleontology“. (10.1080/02724634.2023.2265445)

Original story – Science in Poland 

Researchers are from the Faculty of Biology of the University of Warsaw and the Institute of Paleobiology of the Polish Academy of Sciences.