Some paleontologists have been going overboard with dino-feathers.
“Feathers were the exception, not the rule” says Nature News in a paradigm-correction move. “Survey of dinosaur family tree finds that most had scaly skin like reptiles.” Matt Kaplan doesn’t doubt that birds are evolved dinosaurs, but reports that the field needs a reality check:
Birds evolved from dinosaurs, and dinosaur fossils are often covered with impressions of feathers, which made some palaeontologists speculate whether feathers were a common trait that appeared early in their history. Now a team analysing feathers on the overall dinosaur family tree argues this is taking things too far.
Surprisingly, it’s been the ornithischian dinosaurs (“bird-hipped”) that were scaly, and the saurischian (“lizard-hipped”) that supported the “feathered dinosaur” claims. Evidence of “integumentary structures” on ornithiscians have been rare exceptions. Paul Barrett (Natural History Museum, London) and a colleague made a database of all known dinosaur skin impressions to show that scales were the rule throughout the family tree.
The findings provide “a valuable reality check for all of us who have been enthusiastic about suggesting dinosaurs were primitively feathered”, says Richard Butler, a palaeontologist at the University of Birmingham, UK, who was not associated with the study.
Butler added that there are not any known “primitive dinosaurs from the late Triassic and early Jurassic” to answer the question of the origin of feathers.
As we reported before (list), the scattered appearance of “feathers” (actually, not flight feathers except on real birds) on the dinosaur “family tree” creates real problems for evolution, making paleontologists retreat to the lifeboat of “convergent evolution” to explain their independent appearances (5/28/13). If you can’t imagine a flying triceratops or ultrasaurus, go to the movies, where imagination cures data problems. Darwin would have loved Smaug in Hobbit II.