A new species of fossil turtle, called Dortoka vremiri, was discovered on the territory of the UNESCO Ţara Hațegului International Geopark of the University of Bucharest. Dortoka vremiri survived the event that led to the extinction of the dinosaurs and can provide important clues to stop the extinction of some current animal species due to human activities.
Through this discovery, the Dinosaur Valley of the UNESCO International Geopark Țara Hațegului offers new information on the diversity of life from 70 million years ago, from the former Hațeg Island. Here, paleontologists discovered this species of turtle, contemporary with dwarf dinosaurs from Transylvania. Paleontologists named the new discovery Dortoka vremiri, in honor of the famous Romanian paleontologist Mátyás Vremir, who died in July 2020. Mátyás Vremir had an important contribution to the study of vertebrate fossils discovered in Romania, including the Hațeg area, and was the first to report here the existence of Dortoka-type turtles during the Late Cretaceous. The newly discovered species is part of a larger family of turtles more specific to the southern hemisphere. The fossils as closest relatives date back about 57 million years ago and have been identified in NW Romania. Thus, this new discovery offers an important perspective on the identity of mass extinction survivors, from the end of the Cretaceous, which led to the extinction of the dinosaurs.
The paleontological discovery was documented in a study recently published in the Journal of Systematic Paleontology. The research was conducted by an international team composed of Felix J. Augustin and Andreas T. Matzke from the University of Tübingen (Germany), Zoltán Csiki-Sava from the University of Bucharest (Romania), Gábor Botfalvai from the Museum of Natural History and the University Eötvös Loránd – Budapest (Hungary) and Márton Rabi from the University of Halle-Wittenberg (Germany).The authors of the study represent the universities of Tübingen and Bucharest – CIVIS members, as well as scientific institutions from Hungary with which the Faculty of Geology and Geophysics of the University of Bucharest has concluded a scientific cooperation agreement for paleontological studies on fossils discovered on the current territory of the International UNESCO Țara Hațegului Geopark, for five years.The fossilized specimen is very well preserved and offers a lot of details on this species. The uncovered shell is almost complete, about 19 cm long and oval in shape. The breastplate (abdomen) was kept intact, with a length of 15.5 cm. Both the shell and the breastplate have ornaments characteristic of the Dortoka turtle genus and are thinner than those of their contemporaries, the Kallokibotion turtles, which were significantly larger in size.
“Kallokibotion bajazidi was the first species of fossil turtle identified on the current territory of the Ţara Hațegului Geopark, contemporary with the dwarf dinosaurs. This species was common, as evidenced by its remains, which are found in abundance in the fossiliferous rocks here. The species was described by Franz Nopcsa in 1923, almost a century ago; In a way, our discovery represents a centennial homage to the activity of this important researcher from the Hațeg area, the discoverer of the famous dwarf dinosaurs. The tortoise, unlike the Kallokibotion, was a rarer species. This reason, but also its smaller size, explains how it came to be identified only after a century of research. Even after the discovery of the specimen described by us, it took almost 30 years until we managed to establish its identity”, says professor Zoltán Csiki-Sava from the Faculty of Geology and Geophysics of the University of Bucharest, co-author of the study.In addition to Kallokibotion, which preferred the terrestrial environment, Dortoka was adapted to the aquatic environment, preferring freshwater.
“The only turtle we know that coexisted with the newly discovered species lived on land and did not survive mass extinction. Instead, this new species was a freshwater turtle. This is in line with a pattern previously observed in contemporary North American fauna, where terrestrial vertebrates have disappeared significantly more than freshwater vertebrates in the late Cretaceous period”, said Felix Augustin, PhD student at the University of Tübingen and main author of article.Researchers are considering this hypothesis because aquatic food chains rely heavily on decaying organic matter that can be available even in extreme environmental conditions when terrestrial food chains are destroyed.
By understanding ecological selectivity in the case of past extinctions, the new discovery can support efforts to conserve endangered species due to human activities.The article regarding this discovery can be accessed here, and more information on the Țara Hațegului Geopark is available here.