A paleontological discovery in the Lago Barreales, Neuquén (Argentina) region revealed the existence of a new species of freshwater turtle that inhabited the area approximately 90 million years ago, during the Cretaceous period.
The species, named Elkanemys caelestis, was published in the journal Journal of Systematic Palaeontology and constitutes a key contribution to understanding the evolution of fossil reptiles in South America.
The discovery and its unique characteristics
Elkanemys caelestis was identified from materials collected on the north shore of Lago Barreales by technician and guide Juan Mansilla in 2022. Its remains present a unique anomaly: supernumerary peripheral bones and marginal scutes, a trait rarely documented in fossil turtles of the region.
The name “caelestis,” which in Latin means “celestial,” refers to the bluish color of the remains, highlighted by the contrast with the orange rocks of the site.
The study was conducted by Mariana Sarda and Ignacio Maniel, members of the Institute of Evolution, Historical Ecology and Environment (IDEVEA), under the National Technological University and Conicet, with the support of the Argentine Paleontological Association, the Bunge & Born Foundation, and Conicet.
Evolutionary context: the Pelomedusoides
Elkanemys caelestis belongs to the suborder Pleurodira, characterized by turtles retracting their heads sideways instead of inward. This group, known as Pelomedusoides, survives today in northern South America, Africa, and Australia, although in the past it also extended through Argentine Patagonia.
“The presence of fossil Pelomedusoides in the Patagonian region is scarce. Until this discovery, only two species from the local Cretaceous had been identified, making the new species especially significant,” explained Sarda in an interview with Diario RÍO NEGRO.
Distinctive features of the new species
The fossils exhibit differences in the bones and scutes of the carapace and plastron, protective structures unique to turtles. This allowed Elkanemys caelestis to be recognized as a new species.
Among the most notable features are:
- Anomaly in the carapace: supernumerary peripheral bones and marginal scutes.
- Unusual triangular bone under the dentary, never before described in Cretaceous Pleurodira turtles.
- Hexagonal and quadrangular neurals in a unique arrangement.
- The specimen MUC-Pv 2219 includes the most complete skull known for a Cretaceous Pelomedusoides from Patagonia.
The phylogenetic analysis places Elkanemys caelestis within the Podocnemidoidae group, with close links to fossil species from the Bauru Basin in Brazil.
Scientific and regional importance
The specimens were recovered from outcrops of the Portezuelo Formation, within the Neuquén Basin, and cataloged at the Museum of the National University of Comahue.
The discovery reinforces the importance of paleontological study of turtles to reconstruct South American ecosystems and understand the evolutionary history of Pelomedusoides. Additionally, it provides unprecedented evidence of the diversity of fossil reptiles in Patagonia.
The research team especially acknowledged the work of those who collaborated in the campaign, such as the Dino Project, founded by Jorge Calvo, along with Mansilla, Laura Ávila, IDEVEA members, Javier Guevara, Marcos Jannello, and Dr. Marcelo de la Fuente.
With the incorporation of Elkanemys caelestis into the Argentine and global fossil record, paleontology adds a key piece to understanding the evolution of turtles and prehistoric reptiles in South America. This discovery not only expands scientific knowledge but also highlights the importance of Patagonia as a territory of unique findings.
Cover photo: Tomás Jara
