If you think of Transylvania, you can imagine a place inhabited by vampires and werewolves. You can now also add “dwarf dinosaurs” to this list. A group of researchers recently identified and named a new dinosaur species from the area. Transylvanosaurus platycephalusor “The flat-headed reptile from Transylvania.” And it’s part of a group of dwarf dinosaurs that evolved to be much smaller than their relatives.
T. platycephalus, A member of the Rhabdodontidae family – a group of herbivorous ornithopod dinosaurs – lived as late as about 70 million years ago. Cretaceous period (145 million to 66 million years ago). At this point in Earth’s past, flowering plants – and with them the first pollinators – had evolved, and the ancient ancestors of birds were just beginning to experiment with flight. great super continent pangea it was divided into several smaller continents, and Europe was an archipelago of tropical islands more like present-day Indonesia or the Galapagos.
In a new study published online Nov. Journal of Vertebrate Paleontology (opens in new tab)In , the researchers identified the newly found species from bone fragments taken from the forehead and lower back of the skull. In life, T. platycephalus it would have been just 6.5 feet (2 meters) long. It had a broad, flat head and lived with other reptiles such as crocodiles and turtles.
Related: Ancient Transylvanian tortoise survived the extinction of the dinosaurs
previous research suggested (opens in new tab) Dinosaur diversity had decreased significantly at this point in Earth’s history, just before the mass extinction that ended the Cretaceous. But this new finding may suggest that various forms of dinosaurs were still largely a part of the landscape of Cretaceous Europe.
“With each newly discovered species, we are refuting the common assumption that Late Cretaceous fauna had a low diversity in Europe.” Felix Augustin (opens in new tab)lead study author and PhD candidate at the University of Tübingen in Germany, said in a statement Declaration (opens in new tab).
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The dinosaur’s tiny size makes it the newest member of the so-called dwarf dinosaur family found in Romania’s Hateg region (Transylvania is the historical and cultural name for the region in Central Romania). The Hateg dwarf dinosaurs are a notorious group of dinosaurs that have fascinated paleontologists since their discovery in the early 20th century. Another group of researchers in 2010 determined During the Late Cretaceous period, an island of about 30,900 square miles (80,000 square kilometers) stretched in the area of Hateg, where these dwarf dinosaurs were found.
Islands often produce smaller-than-normal species. Today, there is dwarf lemurs On an island in northern Madagascar and the dwarf foxes on the California Channel Islands. Ten thousand years ago, the dwarf elephants and dwarf hippos He lived on islands in the Mediterranean. In a study published in 2021 in the journal Nature Ecology and Evolution (opens in new tab)The researchers analyzed thousands of reports of body size changes for more than a thousand species and found that the “island rule” is generally true – as generations pass, large animals tend to shrink when isolated on an island.
There are several hypotheses behind why animals are shrinking on an island. The absence of large predators may be allowing animals to remain small, as evolutionary anthropologist Caitlin Schrein wrote in the journal anthropology in 2016. sapiens. Schrein wrote that island ecosystems may offer less diversity in food, perhaps leading to stunted growth in some animals. And if there are no large predators on the island, these small animals will not be removed from the population.
During the Late Cretaceous, Rhabdodontidae dinosaurs were the most common small to medium-sized herbivores found in what is now Europe. In the new study, the researchers found that their relatives T. platycephalus found in present-day France, which would then be a separate island. As archipelagos formed and sea levels fluctuated, land bridges between islands could have allowed dinosaurs to spread and evolve in isolation from one another.
Augustin suggested that they might even have swam short distances and dispersed between the islands. Dinosaurs “had strong legs and a strong tail. Most species, especially reptiles, can swim from birth,” Augustin said.