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70 million years ago, a previously unknown, rather flat-headed dinosaur lived on an island home to dwarf prehistoric creatures.
Transylvanosaurus platycephalus (flat-headed), currently discovered in Western Romania Reptile from Transylvania) was 2 meters (6 feet) long – a relatively small size for a dinosaur, according to a new study. Skull bones were unearthed in a riverbed of the Haţeg Basin in 2007.
During the Cretaceous Period, this part of Romania was a tropical archipelago. Dinosaurs that lived there smaller than their relatives elsewhere; paleontologists believe that these dinosaurs An example of what biologists call the “island rule” is when large animals isolated on islands become dwarfed or stunted in growth over time and small animals become larger.
Sauropods, the largest dinosaur species to have ever lived, reached an average height of 6 meters (about 20 feet) in the archipelago, compared with the 15 to 20 meters (49.2 to 65.6 feet) typical for the group.
However, the mechanism causing 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 as the sediments of an ancient riverbed preserved them.
Felix Augustin, a paleontologist and PhD co-author of the study, said, “If the dinosaur had died and lay on the ground instead of being partially buried, the weather and scavengers would soon have destroyed all its bones, and we would never have found out.” Student He said in a news release at the University of Tübingen in Germany.
None of the bones the researchers uncovered It was more than 12 centimeters (about 5 inches) long, but they did reveal a remarkable amount of detail about the small plant-eating dino that walked on two legs and had a strong, thick tail. The research team said it was possible to distinguish the contours of the Transylvanosaurus’ brain.
“We were able to see impressions and thus proportions of different brain parts – more specifically, olfactory bulbs (the part of the brain responsible for the sense of smell) and the brain that serve many different functions, from sensory processing to memory,” Augustin said via email.
“The next step would be to compare the proportions of the brain and eye with those of other related species, as this could provide information about which senses were important to Transylvanosaurs,” he added.
The Haţeg Basin has been a hotbed for dinosaur discoveries. This dinosaur species was already identified during excavations in the area, with the first dinosaur discovered in 1900. Transylvanosaurus platycephalus It’s the first new dinosaur species to be discovered here in 10 years, after a small carnivore and long-necked plant-eater was found in 2010, Augustin said.
Transylvanosaurus was a plant eater and part of a family of dinosaurs known as the Rhabdodontidae, common in the Late Period. Cretaceous Period. The study said its head is much wider than that of other Rhabdodontidae species.
Exactly how Transylvanosaurus ended up in the eastern part of the European archipelago remains unclear.
Researchers believe this dinosaur species may have originated in present-day France, where the fossils of its closest relatives are found, and may have reached the area somehow—perhaps by swimming or due to sea-level fluctuations or tectonic processes. formed a land bridge.
“It had strong legs and a strong tail,” Augustin said of Transylvanosaurus. “Most species, especially reptiles, can swim from birth.”
Another possibility is that the various rhabdodontid species evolved in parallel in the East and West. Europe.
Whatever their geographic origins, the newly discovered species help disprove assumptions that dinosaurs and other faunal diversity was low during the Late Creaceous Period, the researchers said. Besides 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 land animal on this island was pretty small,” Augustin said via email. “The one exception was pterosaurs, some of which reached gigantic body sizes – probably because they could fly and therefore were not so severely affected by the limited resources on the island.”
The research was published in the US on November 23. Journal of Vertebrate Paleontology.
