Why Did the Tyrannosaurus Have Such Tiny Arms?

As you probably know, the tyrannosaurus was a large carnivorous dinosaur that lived in the Cretaceous period. This period ended approximately 65 million years ago. The tyrannosaurus is what comes to mind for many when they think of dinosaurs. It is easily one of the most well known, and iconic dinosaurs.

Although there were larger carnivorous dinosaurs, the tyrannosaurus was one-of-a-kind when it was found. Before its discovery, the only known dinosaurs were less menacing herbivores. When the tyrannosaurus skeleton was discovered, it was very different from the other dinosaurs. For example, it stood on two legs and had sharp teeth, while other known dinosaurs stood on four legs, and had flatter teeth. Because of these characteristics, it got a lot of publicity, which led it to become as well known as it is today.

One strange feature of the tyrannosaurus was its tiny arms. Scientists used to believe they were just an evolutionary defect, left behind by its four-legged ancestors, but new research suggests that they might have actually had some use. In very young tyrannosaurus skeletons, the arms were much bigger in proportion to the body, and signs indicate that they may have been very muscular.

A tyrannosaurus's early life was tough. The young dinosaurs were only a fraction of the size of the adults, and were not yet the top predator they would become if they survived through childhood. They had to constantly avoid predators, hunger, and disease. During the first 13 years of its childhood, a tyrannosaurus would gain about three kilograms a day. It took a tyrannosaurus 20 years to reach adulthood. The adults could be over 12 meters long and weigh over seven metric tonnes. Now it was at the top of the food chain, and few predators would prey on it.

New studies show that in its early years, a tyrannosaurus would use its arms to catch and eat prey. After it reached adulthood, it would either hunt creatures too large to grasp in its hands or be able to catch prey directly in its mouth. At this point in its life, a tyrannosaurus’s arms were no longer as useful. They were also much smaller in proportion to its body than before. These studies also show that using its arms to grab prey might have evolved from tyrannosaurus’s earlier cousins, which were smaller and faster. Other findings from the study revealed that the tyrannosaurus also had more feathers than originally believed.

These new studies are still taking place, so there is still a lot of information that has yet to be uncovered. Through the years, new discoveries and theories have continuously been made about the tyrannosaurus and other dinosaurs. An example of this is how scientists used to think the tyrannosaurus stood up straight, with its tail touching the ground, but scientists now know it walked more hunched over. Discoveries like this show how much people still do not know.

[Source: Livescience.com ]