Researchers have just identified the oldest-known ancestor of the dinosaur, and what they have discovered is changing scientists’ view of the evolution of the ancient reptiles.
Bones from what is now termed the Teleocrater rhadinus were first discovered in Tanzania several decades ago, but there were not enough remains to put together an identifiable skeleton. A more recent find near the same area in 2015 led to the discovery of more fossilized bones, which have allowed paleontologists to form a more accurate picture of the dinosaur ancestor’s size and shape. Their findings have been surprising.
It had always been assumed that predator dinosaurs and their ancestors walked on two legs, but the Teleocrater, also a carnivorous predator, walked on all fours like a crocodile. It also had ankles similar to a crocodile’s, unlike the bird-like ankles found in later dinosaurs. It would have borne similarities to the modern Komodo dragon in appearance, while also having some crocodilian and dino-like features.
Scientists were also surprised by the reptile’s size. Many paleontologists have long believed that the earliest dinosaur ancestors would have been small, perhaps the size of a chicken. The Teleocrater, though, was surprisingly large. It would have measured between seven to ten feet in length, which is smaller than many full-grown crocodiles, but much larger than expected.
In addition to its crocodilian features, the Teleocrater boasted several dinosaur characteristics. Among these were depressions for jaw muscle attachments on the roof of the skull and typical hip muscle attachments on the thigh bones.
The reptile, which lived roughly 245 million years ago, during the Triassic Period, and about 10 million years before the first appearance of dinosaurs. The Teleocrater is more of a cousin to the dinosaur than a direct ancestor, and its descendants would become such diverse species as birds and crocodiles, as well as the myriad species of dinosaurs.
The findings have led scientists to draw some important conclusions. First, they now believe that dinosaur features accumulated slowly over thousands of years, instead of evolving in a short span of time, as was previously believed. In addition, ancestors to the Teleocrater had already been found in such far-flung locations as India, Brazil, and Russia, meaning that these early dinosaur relatives were spread all over the globe.
Researchers are hopeful that this discovery, and others like it, will lead to a much greater understanding of the origins of dinosaurs, birds, and modern reptiles.