Discovered predator, before which trembled tyrannosaurs - Gazeta Wyborcza

Siats meekerorum, predatory dinosaur before 98 million years (Photo by Jorge Gonzales)

This new species of carnivorous dinosaur – one of the largest, which once lived in North America. Predator by millions of years of terrorizing the continent, holding in check even the famous tyrannosaurs.

The mighty dinosaur skeleton fragments, which called Siats meekerorum (siats – from the name of the monster-cannibal tribe of Native American myths Jutes), encountered paleontologists with the Museum of Natural History of North Carolina and Chicago in the USA. The finding described in “Nature Communications.”

The fossil dates back 98 million years old, belonged to an individual with a size greater than 10 m, which must have weighed at least 4 tons. And while it was a dinosaur young, not yet fully developed.

Discoveries – Lindsay Zanno and Peter Makovicky – believe that an adult reached sizes akrokantozaura, who was one of the largest theropods (predatory dinosaurs), grew to 12 m and weight of more than 6 tons. Akrokantozaury lived on the same land 10 million years ago.

Both species – Siats meekerorum and akrokantozaura – are members of the family karcharodontozaurów, including the largest carnivores history. Second only predator of all time – the famous Tyrannosaurus rex, which was even more powerful bulk. But T. rex roamed a good 30 million years later, he was one of the last dinosaurs lived period of mass extinction 65 million years ago.

As the researchers say, much earlier – by a significant part of the later Cretaceous – ruled the continent of North America karcharodontozaury, including just discovered Siats meekerorum. Tyrannosaurids at this time were smaller and had to give way to the way. – Karcharodontozaurom probably caused so much trouble, which today hyenas lions – says one of the discoverers.

Only when powerful competitors died, about 88-90 million years ago (probably as a result of climate change and ecosystem), tyrannosaurs could grow in strength and take their place in the last 20 million years of the Cretaceous period. Then ascended to the throne of Tyrannosaurus rex.