Feathers may have evolved in the earliest of dinosaurs, not only among the theropods that evolved into birds, surmise surprised paleontologists eyeing a new-found fossil herbivore with the tell-tale plumes - as well as scales, found in Siberia.

This is the first dinosaur found with feathers that isn't a theropod, which is the family including the likes of T-rex and velociraptors, says the team of paleontologists, led by Pascal Godefroit of the Royal Belgian Institute of Natural Sciences.

Kulindadromeus zabaikalicus was a meter-long plant-eater dating from the middle Jurassic (the era after the Triassic). It seems to have looked rather like a giant chicken, with tiny little arms like a miniature T-rex, a short snout, and a lizard-like long tail.

Not only did this peaceful plant-eater have feathers – it also had scales, leading the paleo team leading the study to conclude in their paper published in Science that "featherlike structures coexisted with scales and were potentially widespread among the entire dinosaur clade."

The beast had small scales on its shins and bigger ones on its tail. It seems to have had a downy plume on the head and more featherlike structures on its chest and legs.

Based on fossil finds so far, theropods and the dinosaurian ancestors of the birds split 220 million years ago, indicating that they shared a feathered ancestor. With this discovery, paleontologists are wondering whether all early dinosaurs had proto-feathers.

The first feathered dinosaur was found in 1996 in China. Many have since come to light. One reason feathered fossils are hard to find is that the filaments are finer than bones and don't last well. n

Scientists believe that feathers originally evolved as insulation, like fur - a body covering for warmth that had nothing to do with flight. The adaptation of the feather to flight was a later development, they think.

Some also postulate that exotic coloring in the feathers served in communications, based on the fact that birds and animals use body colors to signal. (Think peacock fanning its tail, or baboon presenting its bright-red rear as sexual signals; or us wearing bright clothing, jewelry, and so on.)

If we assume that all Triassic dinosaurs had feathers, then we must conclude the feathery coat disappeared in some animals, for instance the ones like ankylosaurs which developed armor.

Four wings but couldn't fly

Earlier this month China's fertile fossil fields produced yet another feathered weirdo – an animal with four wings that, nonetheless, the paleo set thinks couldn't fly, certainly not well. At most it may have glided from treetops, they speculate.

This one was a meat-eater named Changyuraptor yangi, and had extraordinarily long tail feathers - the longest found in any dinosaur so far – a good 30 centimeters in length.

Like our giant beakless chicken, the yangi had feather-covered forelimbs akin to wings as well as legs covered in feathers, leading paleontologists to speculate that it sort of glided like a "flying squirrel" with four wings. This was no midget either, at about 1.3 meters long, and though it looked rather like a bird - it was not, say the paleos. The earliest-known real bird is the famous Archaeopteryx, which lived about 150 million years ago.

Open gallery view The fossil feathers found on Kulindadromeus zabaikalicus' femur.

Open gallery view A simiar find - the fossil Microraptor gui was preserved with its feathers intact: The arrows point at some. Credit: Wikimedia Commons