Archaeopteryx had feathers before flight - but why?
Archaeopteryx is the most famous of the flying dinosaurs, and a new specimen of the animal reveals the species developed feathers before learning how to fly.
Ludwig-Maximilians-Universität (LMU) researchers in Munich, Germany discovered previously-unknown features of Archaeopteryx plumage. This could suggest a use for feathers that predates their employment for flight.
Archaeopteryx lived around 150 million years ago, during the late Jurassic period. Its name means ancient wing, and the first fossil of its kind was discovered 150 years ago.
The newest Archaeopteryx to be discovered is the 11th confirmed fossil in the genus. This one has the best-preserved feathers of any member of the collection. The detail in feathers is so great that they allow extensive comparisons to other feathered dinosaurs, which were never before possible. Feathers were easily observed all over the body of the ancient bird, including the body and legs of the animal.
"Comparisons with other feathered predatory dinosaurs indicate that the plumage in the different regions of the body varied widely between these species. That suggests that primordial feathers did not evolve in connection with flight-related roles, but originated in other functional contexts," Christian Foth of LMU said.
Theropods, a type of dinosaur now known to predate Archaeopteryx, also had feathers, but could not fly. Paleontologists believe the covering provided these species a way of keeping their bodies warm. Some advanced species of feathery dinosaurs could have also used tails for balance, in much the same way ostriches do today. The colorful adornments could also have been used simply for display, attempting to attract mates. Animals that flew soon adapted the body parts for other purposes.
"Interestingly, the lateral feathers in the tail of Archaeopteryx had an aerodynamic form, and most probably played an important role in its aerial abilities," Foth stated in a press release.
Feathers adapted for flight would need to have specific characteristics, so variation between them should be small. But, early feathers show wide variations in location and structure. This suggests the parts developed before dinosaurs took to the air.
"It is even possible that the ability to fly evolved more than once within the theropods," Oliver Rauhut, a paleontologist in the Department of Earth and Environmental Sciences at LMU Munich, told the press.
All Archaeopteryx fossils found so far were discovered in limestone deposits in the Altmühl valley of Bavaria, in a shallow sea. During the height of Archaeopteryx, the area was located in the northern tropics.
Investigation of the new Archaeopteryx fossil and the role of feathers in pre-flight evolution was published in the journal Nature.