Another “feathered dinosaur” story has caused a flap and flurry of news reports. But are they really feathers, and do they help evolutionary theory?
An exceptionally preserved juvenile in typical “dinosaur death pose” was unearthed in German limestone and given the name Sciurumimus (“squirrel-mimic”). Labelled Jurassic by the researchers who announced the discovery in PNAS,1 this is the first non-coelurosaur species described with integumentary structures. It is leading some to postulate that all the branches of dinosaurs had “feathers,” as stated in National Geographic’s article: “‘Probably all dinosaurs were feathered,’ scientist concludes.”
One will look in vain, though, for veined feathers with barbs and barbules as found in birds. The authors label the structures “type 1 feathers,” meaning single filaments protruding from the skin (see 9/15/2011 entry). They are actually little more than fuzz, barely noticeable in the photos. Co-author Helmut Tischlinger said, “Under ultraviolet light, remains of the skin and feathers show up as luminous patches around the skeleton.” Some, like Brian Switek at Nature News, dub them “protofeathers.” He wrote,
Palaeontologist Paul Barrett of London’s Natural History Museum agrees that the structures on Sciurumimus are probably protofeathers. Although additional geochemical work is needed to study the features’ details, Barrett says, the fossilized wisps are very similar to the fuzz seen on other dinosaurs. But he notes that the presence of these filaments among all dinosaurs is “speculation”. Feathery structures might be a common feature of dinosaurs, but it’s also possible that they evolved multiple times. “We need more examples in both non-coelurosaurian theropods, and particularly in the other big dinosaur groups, before we can really speculate that these features are a character of dinosaurs as a whole,” Barrett says….
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