Were all dinosaurs feathered? Including scaled herbivores?
Apparently, maybe so. The first ever example of a fossil of a plant-eating dinosaur with feathers and scales was recently discovered by researchers in Russia. Before this discovery only meat-eating dinosaurs were known to have had feathers — the new fossil discovery upends many previous assumptions.
The new dinosaur species has been named Kulindadromeus zabaikalicus, after the site that it was discovered at, known as Kulinda — on the banks of the Olov River in Siberia. The new findings are described in a paper published in the journal Science.
The press release provides more:
Kulindadromeus shows epidermal scales on its tail and shins, and short bristles on its head and back. The most astonishing discovery, however, is that it also has complex, compound feathers associated with its arms and legs.
Birds arose from dinosaurs over 150 million years ago so it was no surprise when dinosaurs with feathers were found in China in 1996. But all those feathered dinosaurs were theropods, flesh-eating dinosaurs that include the direct ancestors of birds.
The Kulinda site was found in summer 2010 by Professor Dr Sofia Sinitsa from the Institute of Natural Resources, Ecology and Cryology SB RAS in Chita, Russia. In 2013, the Russian-Belgian team excavated many dinosaur fossils, as well as plant and insect fossils.
The feathers were studied by Dr Maria McNamara (University of Bristol and University College, Cork) and Professor Michael Benton (University of Bristol), who has also worked on the feathers of Chinese dinosaurs, and Professor Danielle Dhouailly (Université Joseph Fourier in Grenoble, France) who is a specialist on the development of feathers and scales in modern reptiles and birds.
Lead author Dr Pascal Godefroit from the Royal Belgian Institute of Natural History in Brussels stated: “I was really amazed when I saw this. We knew that some of the plant-eating ornithischian dinosaurs had simple bristles, and we couldn’t be sure whether these were the same kinds of structures as bird and theropod feathers. Our new find clinches it: all dinosaurs had feathers, or at least the potential to sprout feathers.”
Dr McNamara said: “These feathers are really very well preserved. We can see each filament and how they are joined together at the base, making a compound structure of six or seven filaments, each up to 15mm long.”
Professor Dhouailly stated: “Developmental experiments in modern chickens suggest that avian scales are aborted feathers, an idea that explains why birds have scaly legs. The astonishing discovery is that the molecular mechanisms needed for this switch might have been so clearly related to the appearance of the first feathers in the earliest dinosaurs.”
The new findings suggest that feather-like structures were probably very common in dinosaurs — and, also, possibly present since the beginning of the lineage.