A flat-headed dinosaur lived on an island full of dwarf creatures

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A previously unknown dinosaur with a noticeably flat head lived about 70 million years ago on an island home to prehistoric creatures.

Discovered in what is now western Romania, Transylvanosaurus platycephalus (Flathead The reptile from Transylvania was 2 meters (6 feet) long – a relatively small size for a dinosaur, According to a new study. His skull bones were discovered in 2007 in a riverbed in the Haţeg Basin.

In the Cretaceous period, this region of Romania was a tropical archipelago. Dinosaurs used to live there smaller than their relatives elsewhere; Paleontologists believe that these dinosaurs were An example of what biologists call “island rule,” in which large animals isolated on islands become dwarfed or stunted in their growth over time and smaller animals become larger.

Sauropods, the largest type of dinosaur that ever lived, averaged 6 meters (about 20 feet) in height in the archipelago, for example, compared to the 15 to 20 meters (49.2 to 65.6 feet) typical of the group.

However, the mechanism leading to such changes is not fully understood but may be linked to a lack of resources.

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

“If the dinosaur had died and lay on the ground instead of being partially buried, the weather and the rubbish would have destroyed all of its bones soon and we wouldn’t have learned anything about it,” said co-author Felix Augustin, paleontologist and Ph.D. student at the University of Tübingen in Germany, he said in a press release.

The researchers did not uncover any of the bones It was over 12 cm (about 5 inches) longer, but they revealed a wonderful amount of detail about the small, plant-eating dinosaur that would have walked on two legs and had a thick, sturdy tail. The research team said it was possible to discern features of the brain of Transylvanosaurus.

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

“The next step would be to compare the brain-eye proportions of other related species, as this may give information about what senses were important to Transylvanosaurus,” he added.

The Haţeg Basin has been a hotbed of dinosaur discoveries. Ten species of dinosaurs have already been identified during excavations in the area, with the first dinosaur discovered in 1900. Transylvanosaurus Platycephalus It is the first new species of dinosaur to be discovered there in 10 years after a small carnivore and a long-necked herbivore were found in 2010, Augustin said.

Transylvanosaurus was a plant-eater and part of the dinosaur family known as the Rhabdodontidae that was popular during the late modern era. Cretaceous period. Its head was much wider than that of other Rhabdodontidae, the study said.

It remains unclear exactly how Transylvanosaurus ended up in the eastern part of what used to be the European archipelago.

Researchers believe that this type of dinosaur may have originated in what is now France, where the fossils of its closest relatives have been found, and somehow got to the area – perhaps by swimming, or by fluctuations in sea level or by tectonic processes. Create a land bridge.

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

Another possibility is that different lineages of rhabdodontid species evolved in parallel in the eastern and western regions Europe.

Regardless of their geographic origins, the researchers said, the newly discovered species help disprove assumptions that there was low diversity of dinosaurs and other animals in the late Pleistocene. In addition to dwarf dinosaurs, the Haţeg Basin was also home to crocodiles, giant pterosaurs (flying reptiles), and turtles—before the dinosaurs went extinct 66 million years ago.

“Almost every wild animal on this island was very small,” Augustine said via email. “The pterosaurs were an exception, some of which reached huge body sizes – the reason being that they could fly and were therefore not severely affected by the limited resources on the island.”

The research was published on November 23 in the Official Gazette Journal of Vertebrate Paleontology.