The evolution of feathers

Ed Yong has a nice discussion of a recent paper about a feathered dinosaur over at his blog (Not Exactly Rocket ScienceTianyulong – a fuzzy dinosaur that makes the origin of feathers fuzzier).  The neat thing with this fossil is that it suggests that the evolution of feathers might have been a stepwise process, and indeed their origins may have predated the the last common ancestor of the Saurischian and Ornithiscian dinosaurs (see figure below).

Distribution of feathers among dinosaur taxa
Distribution of feather-like structures among dinosaur taxa

One more example of how we are gradually accumulating more and more supporting evidence for evolutionary explanations of the origins of birds.  You can clearly see the feathery “filamentous integumentary structures” in the fossil:

Primary citation: Zheng, X., You, H., Xu, X., & Dong, Z. (2009). An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures Nature, 458 (7236), 333-336 DOI: 10.1038/nature07856

One thought on “The evolution of feathers

  1. Has anyone considered whether the first feathers might have evolved as tactile organs, rather like the mystacial vibrissae of rats and mice? Even the crudest proto-feathers arranged in tufts around the mouth and eyes, along the head-neck crest, on the digits, elbows, knees, and tail, might have been more useful than vision to animals navigating arboreal and brush thickets or tall grass. Feathers might have provided early warning of the approach, bearing, and heading of predators. From such primarily tactile functions, tufts of feathers might have drifted toward usefulness in mating and fighting rituals, and more lately as sensory organs of the airfoil surfaces for sensing conditions of flight such as angle of attack, lift, banking, stalling, turbulence, and so forth.

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