Flying in a fur coat
The best preserved fossils show that pterosaurs were covered in a dense coating of hair-like fibers known as pycnofibers. They may have had several functions including display and protection against parasites, but probably evolved to help keep pterosaurs warm.
Sordes pilosus was the first pterosaur fossil that showed the full extent of pycnofibers. Pycnofibers had been seen as early as the 1830s in German pterosaurs, but they were rare and hard to interpret. Sordes fossils, because of their superb preservation, told the whole story.
- 1
The head, neck, and torso
Covered in a dense pelt, like bats.
- 2
The wings
Also covered with shorter hairs, which might have helped silence the wingbeats.
- 3
Actinofibrils
Thin, stiff fibers in the wing, concentrated at the ends of the wings, which helped make this part of the wing stiffer than the part close to the body.
- 4
The long, curved fifth toe
Part of the rear wing membrane (the uropatagium), which helped control its shape during flight.
Some anurognathids had whisker-like pycnofibers near their mouths, like the specialized bristle-like feathers around the beaks of modern birds like nightjars, which use them to help capture insects.
