A Newly Identified Dinosaur That Lived On An Island Of Dwarf Creatures Had An Unusual Head | CNN

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

Discovered in what is now western Romania, Transylvanosaurus platycephalus (flathead 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 river bed in the Haţeg basin.

In the Cretaceous, this region of Romania was a tropical archipelago. The dinosaurs that lived there were smaller than their relatives elsewhere; paleontologists believe that these dinosaurs were an example of what biologists call the “island rule”, where large animals isolated on islands dwarf or slow in growth over time and small animals grow larger.

Sauropods, the largest type of dinosaur that ever lived, reached average heights of 6 meters (nearly 20 feet) on the archipelago, for example, compared to 15 to 20 meters (49.2 to 65.6 feet ) typical for the group.

However, the mechanism that gives rise to such changes is not fully understood but could be related to a lack of resources.

The dinosaur bones were able to survive for tens of millions of years because the sediments of an ancient riverbed protected them.

“If the dinosaur were dead and just lying on the ground instead of partially buried, weather and scavengers would soon have destroyed all of its bones and we would never have heard of it,” study co-author Felix Augustin, paleontologist and doctoral student student at the University of Tübingen in Germany, said in a press release.

None of the bones discovered by the researchers was over 12 centimeters (about 5 inches) tall, but they revealed a remarkable amount of detail about the tiny herbivorous dino that reportedly walked on two legs and had a powerful, thick tail. It was possible to discern outlines of the brain of the Transylanosaurus, the research team said.

“We were able to see the impressions, and therefore the proportions, of different sections of the brain – specifically, the olfactory bulbs (the section of the brain responsible for smell) and the brain, which performs several 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 to other related species, as this could yield information about the senses that 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 being discovered in 1900. Transylvanosaurus platycephalus is the first new dinosaur species to be discovered there in 10 years after the discovery of a small carnivore and a long-necked plant-eater in 2010, Augustin said.

Transylvanosaurus was a plant eater and part of a family of dinosaurs known as the Rhabdodontidae which were common in late Cretaceous period. Its head was much larger than other Rhabdodontidae species, according to the study.

It is unclear exactly how the Transylvanosaurus ended up in the eastern part of what was the European Archipelago.

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

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

Another possibility is that various lineages of rhabdodontid species evolved in parallel in the East and West. Europe.

Regardless of its geographic origins, the newly discovered species helps disprove hypotheses that there was low diversity of dinosaurs and other animals during the Late Creaceous, the researchers said. Besides dwarf dinosaurs, the Haţeg Basin was also home to crocodiles, giant pterosaurs (flying reptiles) and turtles – before the dinosaurs died out 66 million years ago.

“Almost all of the land animals on this island were quite small,” Augustin said via email. “An exception were the pterosaurs, some of which reached gigantic body sizes – the reason for this is probably that they could fly and were therefore not so badly affected by the island’s limited resources.”

The research was published Nov. 23 in the Journal of Vertebrate Paleontology.