Guanlong

Guanlong is a genus of tyrannosauroid dinosaur that lived during the Late Jurassic period, approximately 160 million years ago. Its name, meaning "crown dragon," refers to a distinctive crest on its skull. Guanlong was a relatively small theropod, estimated to be around 3 meters (10 feet) in length and weighing about 50 kilograms (110 pounds). It possessed long arms with three-fingered hands, a feature that would later be reduced in its larger tyrannosaur descendants.

The most notable feature of Guanlong is its prominent, fan-shaped crest, which ran from the front of its snout to the back of its skull. The exact function of this crest is debated among paleontologists. It may have been used for display, such as attracting mates or intimidating rivals, or it could have helped regulate body temperature. Guanlong's fossils were discovered in the Upper Shishugou Formation in Xinjiang, China. It is considered one of the earliest known tyrannosauroids, providing valuable insights into the evolutionary history of the Tyrannosaurus Rex lineage. Its discovery has helped fill gaps in our understanding of how these apex predators evolved from smaller, more primitive ancestors.