Dinosaurs may have had feathers more often than once believed, according to new fossils discovered in Siberia.
Paleontologists are beginning to understand that birds are closely related to dinosaurs. One of the ways researchers hope to understand this connection is by learning when feathers first evolved in the prehistoric animals.
Dinosaurs may have exhibited feathers from the time they first evolved, roughly 240 million years ago, according to the new study.
Feathers may have evolved in dinosaurs as a means of attracting mates, or a means of providing insulation for the animals. Thousands of species of dinosaurs have been discovered that exhibited some form of feathers.
The earliest fossils with fully-developed feathers date to around 150 million years in the past, about the same time that the first birds were taking to the air. Other specimens, including the 160-million-year-old Tianyulong from China and Psittacosaurus, a relative of Triceratops that lived 40 million years later, show primitive, feather-like structures.
These early examples of filamentous features cold provide evidence that feathers evolved well before the evolutionary split between meat-eating saurischians and ornithischians, which were herbivores. Birds developed from saurischians, even if the names are confusing. This evolutionary divide took place 200 million years ago.
Kulindadromeus zabaikalicus, which lived 175 million years ago, appears to have sported a complex arrangement of feathers and proto-feathers on its body. Advanced feathers, like those required for flight, covered the arms and legs of the animals, while simpler structures were present over most of the body.
Partial skulls of six of these individuals were discovered in Siberia, in Kulinda. Along with those artifacts, researchers discovered bones from hundreds of other fossils.
"For the first time we found more complex, compound structures, together with simpler hairlike structures [in a herbivore] that really resemble the protofeathers in advanced [carnivores]" Pascal Godefroit, paleontologist at the Royal Belgian Institute of Natural Sciences in Brussels, said.
The feathers of K. zabaikalicus were not designed for flying - that ability was not possible with the simple structures covering most of its body.
Bird-like dinosaurs now appear to be the only animals of their type to survive an impact form a massive asteroid, approximately 65 million years ago.
"Kulindadromeus seals the deal that some plant-eating dinosaurs had feathers, and is the best proof yet that feathers weren't something that evolved only in the meat-eating dinosaurs. It tells us that feathers must have arisen earlier in dinosaur evolution than most of us previously thought, and maybe even the common ancestor of all dinosaurs had feathers," Stephen Brusatte, paleontologist from the University of Edinburgh in the United Kingdom stated in a press release.
Discovery of the early feathered dinosaur was profiled in the journal Science.
