An article published in the journal “Proceedings of the National Academy of Sciences’ describes the study of fossils of Timurlengia euotica, a horse-sized dinosaur that lived about 90 million years ago of which various bones have been discovered in Uzbekistan allowing to identify this new species. It’s a tyrannosaurus that lived before the famous T.rex: it wasn’t its direct ancestor but provides information on its evolution.
The evolution of T.rex was quite mysterious so far because there was a hole of about 20 million years in the availability of fossil species related to it. The new fossils discovered in the Uzbek area of the Kyzylkum desert between 1997 and 2006 help to understand the steps from horse-sized animals with far from exceptional senses to the most notorious predator of Earth’s history.
Hans Sues, one of the study authors, stated that Timurlengia euotica was a pursuit hunter with sharp teeth. Probably it fed on several large herbivores, especially primitive dinosaurs like the duck-billed ones that lived in the same ecological niche.
The discovery of Timurlengia euotica can help to understand how tyrannosaurs evolved to become the T.rex. The first species of the family lived in the Jurassic, about 170 million years ago, and were slightly larger than a human being. Their evolution lasted about 100 million years but the existence of species such as Timurlengia euotica indicates that 90 million years ago they were still relatively small. This is confirmed by another recent study of fossils of various tyrannosauroids discovered in Idaho.
A particularly interesting feature of the Timurlengia euotica is its skull, which seems a smaller version of that of the T.rex because their other characteristics are very similar. The researchers studied the skull bones they found also with a CT scan that allowed them to reconstruct the structure of its brain and from this point of view they noted a similarity with tyrannosauroids that lived in the late Cretaceous period, about 20 million years later.
The reconstruction of the Timurlengia euotica’s brain structure allows to understand the development of its senses. Just like T.rex, it had to have well-developed sight, smell and hearing but also a high intelligence level by the standards of the animals of that era.
In essence, Timurlengia euotica had the characteristics needed to become a successful predator. It’s conceivable that some other species related to this dinosaur had similar skills and that natural selection led it to grow in size to become the famous T.rex.
