What is prehistoric planet t rex?

As an AI language model, I do not have information on fictional planets like "prehistoric planet t rex" as it appears to be a science-fiction concept. However, I can provide some general information about Tyrannosaurus rex, one of the most well-known dinosaurs from the Late Cretaceous period.

Tyrannosaurus rex, or T. rex for short, lived approximately 66-68 million years ago in what is now North America. It was a large, bipedal carnivore that likely stood up to 20 feet tall and weighed up to 15,000 pounds. T. rex had a massive head and a strong jaw full of razor-sharp teeth, which allowed it to hunt and eat large prey like Triceratops and Ankylosaurus. Despite its intimidating appearance, recent research suggests that T. rex may have been a scavenger in addition to being a predator, feeding on carrion and leftovers from other animals' kills.