A flat-headed dinosaur lived on the island of dwarf creatures

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A previously unknown dinosaur with a rather flat head lived about 70 million years ago on an island inhabited by dwarf prehistoric creatures.

Transylvanosaurus platycephalus (flathead) discovered in what is now western Romania reptile from Transylvania) was 2 meters (6 feet) long—a relatively small size for a dinosaur, according to a new study. His skull was exhumed in 2007 from a riverbed in the Haţeg basin.

During the Cretaceous period, this region of Romania was a tropical archipelago. Dinosaurs lived there it is smaller than its relatives in other places🇧🇷 paleontologists think that these dinosaurs an example of what biologists call the “island rule,” in which large animals isolated on islands become dwarfed or stunted over time and smaller animals grow larger.

Sauropods, the largest species of dinosaur that ever lived, for example, reached an average height of a measly 6 meters (about 20 ft) in the archipelago, compared with the typical 15–20 meters (49.2–65.6 ft) for the group.

However, the mechanism leading to such changes is not fully understood, but may be related to resource scarcity.

Dinosaur bones were able to survive for tens of millions of years because the sediments of the ancient river bed protected them.

“If the dinosaur had died and just lay on the ground instead of being buried, weather and scavengers would have quickly destroyed all of its bones and we would never have known about it,” says paleontologist and co-author Felix Augustine. student According to a press release from the University of Tübingen in Germany.

None of the bones the researchers discovered It was more than 12 centimeters (about 5 inches) long, but they revealed a remarkable detail of a small plant-eating dino that could walk on two legs and had a powerful, thick tail. The research team said that it was possible to distinguish the outline of the brain of Transilvanosaurus.

“We were able to see the impressions and thus the proportions of different parts of the brain—specifically, the olfactory bulbs (the part of the brain responsible for smell) and the cerebrum, which performs several different functions, from sensory processing. memory,” Augustin said via email.

“The next step will be to compare the proportions of the brain and eye with other related species, as this may provide information on what senses were important to Transylvanianosaurus,” he said.

The Haţeg Basin has been a source of dinosaur discoveries. Ten species of dinosaurs have already been identified during excavations in the region, and the first dinosaur was discovered in 1900. Transylvanosaurus platycephalus It is the first new dinosaur species discovered there in 10 years since the small carnivore and long-necked herbivore was discovered in 2010, Augustin said.

Transilvanosaurus was part of a family of herbivorous dinosaurs known as the Rhabdodontidae, which became widespread in recent times. Cretaceous period. According to the study, its head was wider than other Rhabdodontidae species.

Exactly how Transylvanianosaurus ended up in the eastern part of the European archipelago remains unclear.

The researchers believe that this type of dinosaur could have somehow arrived in what is now France, where the remains of its closest relatives have been found – perhaps by swimming or as a result of sea-level fluctuations or tectonic processes. created a land bridge.

“They had strong legs and a strong tail,” Augustin said of Transylvanianosaurus. “Most species, especially reptiles, can swim from birth.”

Another possibility is that different rhabdodontid species evolved in parallel in the East and West. Europe.

Regardless of their geographic origin, the newly discovered species help refute assumptions that dinosaurs and other fauna were less diverse during the late Cretaceous period, the researchers said. In addition to dwarf dinosaurs, the Haţeg basin was also home to crocodiles, giant pterosaurs (flying reptiles) and turtles – before the dinosaurs became extinct 66 million years ago.

“Almost every terrestrial animal on this island was pretty small,” Augustin said via email. “The exception was the pterosaurs, some of which reached enormous body sizes – probably because they could fly and were therefore not severely affected by the limited resources on the island.”

The study was published on November 23 Journal of Vertebrate Paleontology🇧🇷