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A previously unknown dinosaur with a remarkably flat head lived about 70 million years ago on an island home to dwarf prehistoric creatures.
Discovered in what is now western Romania, the Transylvanosaurus platycephalus (flat-headed Transylvanian reptile) was 2 meters (6 feet) long, a relatively small size for a dinosaur, according to a new study. The skull bones of him were unearthed in 2007 in the river bed of the Haţeg Basin.
In the Cretaceous Period, this region of Romania was a tropical archipelago. Dinosaurs lived there. smaller than their relatives elsewhere; Paleontologists believe that these dinosaurs were an example of what biologists call “island governance,” where large animals isolated on islands become small or stunted over time and small animals become larger.
Sauropods, the largest type of dinosaur that ever lived, reached average heights of a paltry 6 meters (nearly 20 feet) in the archipelago, for example, compared with 15 to 20 meters (49.2 to 65.6 feet) typical of the group.
However, the mechanism that gives rise to such changes is not fully understood, but it could be related to the scarcity of resources.
The dinosaur bones were able to survive for tens of millions of years because sediments from an ancient river bed protected them.
“If the dinosaur had died and just lay on the ground instead of being partially buried, the weather and scavengers would soon have destroyed all of its bones and we would never have known about it,” said study co-author Felix Augustin, a paleontologist and Ph.D. . pupil at the University of Tübingen in Germany, in a press release.
None of the bones the researchers discovered It was larger than 12 centimeters (about 5 inches), but they revealed a remarkable amount of detail about the small, herbivorous dinosaur that would have walked on two legs and had a powerful, thick tail. It was possible to discern the contours of the Transylvanosaurus brain, the research team said.
“We were able to see the impressions, and therefore the proportions, of different sections of the brain, more specifically, of the olfactory bulbs (the section of the brain responsible for the sense of smell) and the cerebrum, which serves several different functions, from processing sensory to memory,” Augustin said by email.
“The next step would be to compare the proportions of the brain and eye with other related species, as this may give information about which 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 region, 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 long-necked carnivore and herbivore was found in 2010, Augustin said.
Transylvanosaurus was a herbivore and part of a family of dinosaurs known as Rhabdodontidae that were common during the late Cretaceous period. Its head was much broader than that of other Rhabdodontidae species, according to the study.
Precisely how Transylvanosaurus ended up in the eastern part of what was once the European archipelago remains unclear.
The researchers believe that this type of dinosaur could have originated in what is now France, where fossils of its closest relatives have been found, and somehow made its way to the region, perhaps by swimming, or due to fluctuations in the level of the sea or the tectonic processes that created a land bridge.
“They had powerful legs and a powerful tail,” Augustin said of the Transylvanosaurus. “Most species, particularly reptiles, can swim from birth.”
Another possibility is that several lines of rhabdodontid species evolved in parallel in the East and West. Europe.
Regardless of its geographic origins, the newly discovered species helps refute assumptions that there was low diversity of dinosaurs and other fauna in the late Creaceous 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 went extinct 66 million years ago.
“Almost all the land animals on this island were quite small,” Augustin said by email. “One exception was pterosaurs, some of which reached gigantic body sizes – the reason for this is probably that they could fly and were therefore not affected as badly by the island’s limited resources.”
The research was published on November 23 in the Vertebrate Paleontology Journal.
