Protofeathers were likely to have existed within the common ancestor of dinosaurs

In this paper, I comment on Barrett et al. (2015) "Evolution of dinosaur epidermal structures". Though the original authors made some very interesting results, the conclusions made by them are likely influenced by inappropriate or incorrect assumptions such as very little preserved skin fragments represent whole body covering or dinosaurian integumentary structures might represent a degraded collagen fibres. Therefore, their result might represent small size of current datas or preservational bias rather than actual evolutionary history of dinosaurian feathers.