Deep in the rolling hills of Transylvania, scientists have uncovered one of the richest dinosaur fossil sites ever found in the region.
In an area already famous for its prehistoric discoveries, a newly identified “hot spot” has revealed an astonishing concentration of ancient bones — more than a hundred vertebrate fossils in each square metre, with large dinosaur bones lying almost on top of one another.
The discovery was made by the Valiora Dinosaur Research Group, a team of Hungarian and Romanian scientists who have been exploring the western part of the Hațeg Basin for more than five years.
Their latest findings, published in the scientific journal PLOS ONE, describe an extraordinary fossil site known as “K2,” which has produced over 800 vertebrate remains in an area of less than five square metres.
When the team first came across the site in 2019, they immediately realised it was something special.
Assistant Professor Gábor Botfalvai from Eötvös Loránd University recalled seeing dozens of unusually well-preserved black dinosaur bones shining out from the grey clay layers of a streambed.
From that moment on, the researchers knew the site deserved careful and long-term study.
The K2 site is like a snapshot of life — and death — from about 72 million years ago, toward the end of the age of dinosaurs.
At that time, the Hațeg Basin was a warm, subtropical landscape crisscrossed by temporary rivers. During heavy rainfall, these rivers often flooded and swept across the land, picking up the remains of animals that had died nearby, as well as creatures caught in the floodwaters.
According to the researchers, a small lake once existed at the site. When floodwaters rushed into this calmer area, the current suddenly slowed down.
Animal remains carried by the rivers were dropped and piled up in one location, creating a dense layer of bones in a river delta along the lake’s edge. Over millions of years, these remains were buried and preserved, eventually turning into fossils.
The bones found at the site belong to a wide range of ancient animals, including amphibians, turtles, crocodiles, pterosaurs, mammals and several kinds of dinosaurs. Among the most exciting discoveries are partial skeletons from at least two different types of plant-eating dinosaurs.
One of them is a relatively small species, about two metres long, that mostly walked on two legs. It belonged to a group known as the Rhabdodontidae, which were common dinosaurs in this region during the late Cretaceous period.
The second type, however, is much more significant. The fossils belong to a titanosaur — a massive, long-necked sauropod dinosaur. Until now, no well-preserved titanosaur skeleton had ever been found in Transylvania.
These new remains will allow scientists to study this giant dinosaur in much greater detail, helping them understand its size, structure and place in the dinosaur family tree.
Another important aspect of the discovery is its age. The K2 site is the oldest known vertebrate fossil accumulation in the Hațeg Basin. This means it gives researchers a rare look at the earliest dinosaur communities in the region.
By comparing these fossils with those from younger sites, scientists can track how the ecosystem changed over time and how different dinosaur species evolved and adapted.
The Hațeg Basin has long been a treasure trove for paleontologists, but specialists say this new site is exceptional. With its extraordinary density of fossils and rare dinosaur finds, it is providing a clearer picture of what life was like in Eastern Europe just before the dinosaurs disappeared from the planet.
