New fossil suggests dinosaurs may have all been hairy

Scientists have discovered a new species of dinosaur that had what can only be described as "hair" and "ribbons." The finding has sparked excitement among paleontologists, who say the discovery could shed new light on the evolution of feathers and the origins of flight. The dinosaur, named Ubirajara jubatus, lived about 110 million years ago in what is now Brazil. It was a small theropod, measuring about 2 meters in length and weighing about 5 kilograms. But what sets it apart from other dinosaurs is the presence of what appear to be filaments on its body. "The filaments are unlike anything we've seen before in a dinosaur," said David Martill, a paleontologist at the University of Portsmouth in the UK and one of the authors of a study describing the dinosaur, which was published in the journal Cretaceous Research in February 2021. The filaments are about 15 centimeters long and are arranged in two distinct types: some are thicker and more hair-like, while others are thinner and more ribbon-like. They cover the dinosaur's body, from the top of its head to the tip of its tail. "It's really quite remarkable," said Martill. "We don't know what function they served, but they may have been used for display or insulation." The discovery of filaments on a dinosaur is not entirely new. In recent years, scientists have found evidence of similar structures on a number of dinosaur species, including some of the early ancestors of birds. These filaments, known as "protofeathers," are believed to have been an early stage in the evolution of feathers. But the filaments on Ubirajara jubatus are different. They are more complex and diverse than protofeathers, and they appear to have evolved independently of feathers. "We think these filaments represent a new type of integumentary structure in dinosaurs," said Martill. "They're not protofeathers and they're not true feathers. They're something in between." The discovery of such a unique type of integumentary structure has led some scientists to speculate that there may have been many more types of "hair" and "feathers" on dinosaurs than previously thought. "It's possible that there was a whole world of feather-like structures that evolved independently in different groups of dinosaurs," said Martill. "It's a very exciting possibility." The discovery of Ubirajara jubatus also has implications for the study of the origins of flight. Birds are descended from a group of small, feathered dinosaurs known as theropods, which also included famous species such as Tyrannosaurus rex and Velociraptor. The filaments on Ubirajara jubatus suggest that the evolution of feathers and flight may have been more complex than previously thought. Feathers may have had many different functions, including display, insulation, and even glide-assisted flight. "We used to think that feathers evolved primarily for flight," said Martill. "But now we're starting to realize that there may have been many other reasons for their evolution." The discovery of Ubirajara jubatus is also significant because it provides further evidence of the diversity of dinosaurs that lived in what is now Brazil during the Cretaceous period. Brazil is home to some of the world's most important dinosaur fossil sites, including the famous Serra da Capivara National Park, which contains some of the oldest and most well-preserved dinosaur tracks in the world. In recent years, Brazilian scientists have been leading efforts to uncover new dinosaur species and understand the rich diversity of life that existed in the region during the age of dinosaurs. "The discovery of Ubirajara jubatus is a testament to the importance of continued exploration and discovery in this part of the world," said Martill. "