Tag Archives: feather

Fluffy dinosaurs used to live at the South Pole, this treasure trove of fossil feathers suggests

A treasure trove of fossilized dinosaur and bird feathers has been recovered in Australia. In ages long past, however, these animals lived beyond the southern polar circle.

Image credits Uppsala Universitet.

The finding is particularly exciting as feathered dinosaur fossils, while definitely famous, are relatively rare and found in few locations worldwide. Fossils from Southern Hemisphere originating from feathered dinosaurs are doubly so and have mainly been limited to isolated instances thus far. The finding showcases the unexpected diversity of proto-feathers (early, hair-tuft-like feathers) from meat-eating dinosaurs, and of the earliest feathers used for flight.

Dinos of a feather

“Dinosaur skeletons and even the fragile bones of early birds have been found at ancient high-latitudes before. Yet, to date, no directly attributable integumentary remains have been discovered to show that dinosaurs used feathers to survive in extreme polar habitats,” said Dr. Benjamin Kear from Uppsala University in Sweden, a leading author on the study.

The Australian cache includes 10 fossil feathers, which were entombed in the fine muddy sediment on the bottom of a shallow lake. These fossils represent tufted hair-like ‘proto-feathers’ from meat-eating dinosaurs, together with a downy body and wing feathers from primitive birds that would have been used for flight.

The lake, today in Koonwarra Fish Beds Geological Reserve heritage site some 145 km southeast of Melbourne in Victoria, Australia, was very close to the unique environment of the South Pole during the dinosaurs’ time.

“These Australian fossil feathers are therefore highly significant because they came from dinosaurs and small birds that were living in a seasonally very cold environment with months of polar darkness every year,” said Dr. Thomas Rich of the Melbourne Museum in Australia, who has led numerous expeditions to the Koonwarra locality.

“Our study is thus the first to comprehensively document these remains, which include new specimens that were examined using cutting-edge technologies.”

The team used several microscopic and spectroscopic techniques to analyze the fossil feathers, which they say were preserved in “incredible” detail. Much like feathers today, the fossils have tiny filament-like structures that ‘zip’ the feather’s vanes together during flight. However, unlike modern feathers (which have interlocking structures called ‘barbs’ and ‘barbules’), most of the proto-feathers (seen on smaller dinosaurs) have a very simplified structure. These feathers were likely used for insulation, not flight.

“The discovery of ‘proto-feathers’ at Koonwarra therefore suggests that fluffy feather coats might have helped small dinosaurs keep warm in ancient polar habitats,” said Dr. Martin Kundrát, of Pavol Jozef Safarik University in Slovakia, a leading author on the study.

The team was also able to recover possible remains of melanosomes, the cellular structures that contain color pigments. The feathers themselves likely were a uniformly dark color, with traces across and as distinct bands, according to the team. The dark coloring assisted in camouflage and/or heat absorbance in cold polar climates, while the patterns likely aided as a means of visual communication.

Some of the fossil feathers found at Koonwarra are on display in the ‘600 Million Years’ exhibition at the Melbourne Museum in Australia.

The paper “A polar dinosaur feather assemblage from Australia” has been published in the journal Gondwana Research.

Barbules.

Engineers study the in-depth structure of wings to make better adhesive materials

Bird feathers may be the key to new adhesives and advanced aerospace materials.

Barbules.

A, E, and F show birth feathers under normal magnification and under the microscope. B shows a model of the team’s 3D-printed structures and its behavior during a wing’s upstroke (C) and downstroke (D).
Image credits T. Sullivan, M. Meyers, E. Arzt, 2019, Science Advances.

If you’ve ever toyed around with a feather you’ll know that they somehow pull themselves back together if you take their barbs apart. The structures that underpin this behavior may point the way to novel adhesives and aerospace materials, say researchers from the University of California San Diego.

On the wings of progress

Tarah Sullivan, who earned a Ph.D. in materials science from the Jacobs School of Engineering at UC San Diego, led the research efforts. Her team is the first in roughly two decades to take an in-depth look at the structure of bird feathers without focusing on a particular species.

Based on their observations, the team 3D-printed structures that mimic the vanes, barbs, and barbules of feathers to better understand their surprising properties. This step helped them better see how feathers knit themselves back together after you pull them apart, for example, or how their undersides can capture air for lift while the top of the feather can block air to help with the landing.

Sullivan found that barbules — smaller, hook-like structures that connect feather barbs — are spaced within 8 to 16 micrometers of each other. This distance remained stable throughout bird species, from the hummingbird to the condor, suggesting that it is an important property for flight.

“The first time I saw feather barbules under the microscope I was in awe of their design: intricate, beautiful and functional,” she said. “As we studied feathers across many species it was amazing to find that despite the enormous differences in size of birds, barbules spacing was constant.”

The vane-barb-barbule structure seen in feathers could lead to the development of new materials. Adhesives — similar to Velcro — and materials intended for the aerospace industry are the team’s main areas of interest. Sullivan has already built a prototype adhesive material which she plans on discussing in a follow-up paper.

“We believe that these structures could serve as inspiration for an interlocking one-directional adhesive or a material with directionally tailored permeability,” she said.

Sullivan’s team also took a look at the bones in bird wings. They found that the humerus (the longest bone in the wing) is disproportionately long. This is likely intended to give it enough strength to take the weight of a bird’s body in flight, they say. Because bone strength is limited, and because the humerus carries the brunt of the load during flight, scaling it up proportionately to the rest of the wing just doesn’t cut it. Instead, the bone needs to grow much faster and to a greater relative size to withstand the forces it’s subjected to during flight.

This process by which certain body parts grow at different rates than the body as a whole is known as allometry. Our brains, for example, are allometric, as they grow much faster than the rest of our bodies when we’re young. Our hearts are isometric, as they grow proportionately to the rest of the body.

“Professor Eduard Arzt, our co-author from Saarland University in Germany, is an amateur pilot and became fascinated by the ‘bird wing’ problem. Together, we started doing allometric analyses on them and result is fascinating,” said Meyers.

“This shows that the synergy of scientists from different backgrounds can produce wonderful new understanding.”

The paper “Scaling of bird wings and feathers for efficient flight” has been published in the journal Science Advances.

Birds of a feather — A story of Vikings and pillows

Have you ever wondered what Vikings put in their pillows? Or, a more likely question, have you ever wondered what’s in your pillows? The odds are, if it’s not synthetic, it’s probably feathers from domestic geese or ducks. Well, Vikings also used pillows, and they also filled them with feathers — but the feathers didn’t come from a goose or a duck.

“Eagle-owls,” says Jørgen Rosvold, a postdoctoral fellow in the Department of Archaeology and Cultural History at the Norwegian University of Science and Technology (NTNU) University Museum.

A well-preserved feather fragment found in a grave from the Viking era, about one centimeter long. Even after many hundreds of years, you can see the colors and that this is a feather from a crow. Photo: Jørgen Rosvold, NTNU University Museum.

When I first started going out and photographing birds a couple of years ago, I was advised to look for general traits — the shape of the body, the overall flight patterns, the size, those are all important cues. Things like color can be very deceiving. The same color can look different on a sunny and on a cloudy day, and bird colors often play games even on trained eyes. Telling apart a bird by its feathers can be quite tricky, but telling them apart by a single feather? To me, it seems like a pipe dream, but to Rosvold, it’s just another day.

Rosvold is part of a project from the Norwegian University of Science and Technology which aims to develop methods to identify small bits of feather residue. It’s not always possible to tell what species the feather came from, especially if the feather is a few hundreds of years old.

“Sometimes all you can say for sure is that a feather comes from a duck,” says Rosvold — but not which kind of duck.

“It depends on how well preserved the feather is, the kind of feather and whether the species has close relatives,” he says.

Miniscule barbules, the smallest branches of a feather, are examined under a microscope to identify the kind of bird. Here are two different birds. At the bottom left is a rock ptarmigan, a type of game bird with rings around its barbules. At bottom right is a mallard with triangular growths at the ends of its barbules. Photo: Jørgen Rosvold, NTNU University Museum.

Some feathers (most downy parts of feathers) can be quite telling, allowing a clear identification of its previous owners. But sometimes, things are much more difficult, especially when differences between species are subtle.

“In some cases, if we’re unable to identify a feather beyond the family level with microscopes, we can make more headway using DNA analyses. The analyses are easier when we’ve narrowed down the range of possible birds,” says Rosvold.

An intriguing application of this study is studying the relationship early Vikings had to birds. He analyzed a pillow from a Viking grave dating from 1,200 years ago, and you can still see pigmentation in some of these feathers, as well as some distinctive features. For instance, game birds are recognizable by the rings around their barbules, while duck feathers have distinctive triangular growths. The earlier usage of pillow feathers comes from the year 570 and through the Viking era, though there is evidence that elsewhere, Romans also stuffed their pillows with feathers.

Feathers haven’t only been found in pillows, they’ve also been found in a trove of other archaeological sites, including unlikely places, such as embedded in a sword.

Feather residues in corroded iron from a Viking sword. Perhaps the sword was laid on a pillow? Photo: Jørgen Rosvold, NTNU University Museum.

But unlike today’s pillows, these ancient ones didn’t have feathers from ducks or geese. Instead, Rosvold found feathers from Europe’s largest owl. This can help archaeologists better understand the relationship between these people and the birds. For instance, we know that they were farming eider (large sea ducks) in central Norway, but we don’t know when they started doing so. We also don’t know exactly how this farming went, but we do know that Vikings built nesting boxes and protect the ducks, and harvested large amounts of feathers from them.

“The cooperation goes way back in time. We’ve found a few eider feathers, but also a lot of assorted feathers,” says Rosvold.

Lastly, knowing how to identify bird feathers could not only be helpful for historians but also to solve crimes or save lives, such as for investigators who need to collect evidence. Analyzing feathers from impact with planes or vehicles could also help engineers improve designs to withstand such unfortunate crashes.

It’s remarkable how much detail lies in these microscopic bits of feathers — and how much help they can provide, from Viking pillows to plane designs.