By Sid Perkins
Paleontologists have discovered a fossil partially covered with broad, unbranched filaments — a type of structure previously theorized to exist on primitive feathered dinosaurs but not found until now.
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2009/01/9494.jpg?resize=300%2C180&ssl=1)
Flight feathers on modern birds have a central shaft and stiff fibers, called barbs, that branch from that shaft. Barbules, smaller fibers that branch from the barbs, are tipped with small hooks that latch on to adjacent barbs or barbules, stiffening the feather into a single vane.
This arrangement is so complicated that many scientists theorize it could have evolved only once (SN: 8/18/01, p. 106). But paleontologists have proposed that a variety of simpler structures — including peculiar, branched structures colloquially called “dinofuzz” — evolved before feathers. Now, researchers have finally found an important yet long-missing piece of the feather lineage: single, unbranched filaments.