Fossilised Bird and Dinosaur Feathers from Australia
Palaeontologists know that dinosaurs roamed high latitudes, that is to say that fossil finds have demonstrated that dinosaurs once inhabited parts of the world that are now in the Arctic Circle and similar fossil discoveries have been made in the Southern Hemisphere demonstrating that the Dinosauria also inhabited Antarctica.
Although, the climate during the Mesozoic was much warmer than it is today, in these high latitudes the fauna and flora would still have had to endure challenging conditions, such as freezing temperatures and many months of darkness with the sun not rising above the horizon. It has been suggested that many dinosaur residents were feathered, their integumentary coverings of protofeathers and down helping to keep them warm.
However, actual evidence of fossilised feathers was lacking, but scientists writing in the journal “Gondwana Research”, describe several feathers from the Lower Cretaceous-aged sediments at the Koonwarra Fish Beds Geological Reserve located in Victoria (Australia).
A Fossilised Feather from the Koonwarra Fish Beds Geological Reserve
Picture credit: Kundrát et al (Gondwana Research)
Different Types of Feathers Found
Researchers from the Pavol Jozef Safarik University (Slovakia), Monash University, Swinburne University of Technology (both in Australia), Lund University, Uppsala University (Sweden) and from the Natural History Museum of Los Angeles County (USA) in collaboration with other colleagues have identified the first record of avian and non-avian integumentary structures described from Mesozoic polar regions.
In essence, feathered dinosaurs and birds were present at a latitude of around 70 degrees south between 118-115 million years ago. Finding feathers this far south reinforces the view that feathered dinosaurs were ubiquitous for much of the Mesozoic.
Importantly, the handful of fossilised feathers from this site show a lot of variation. Some fossils consist of the preserved remains of tufted body feathers, whilst others show asymmetrical bird-like flight feathers. Fossils of simple, open-vaned contour feathers reminiscent to those of the Liaoning theropod Caudipteryx have also been found.
A Tufted Body Feather from the Koonwarra Fish Beds Geological Reserve
Picture credit: Kundrát et al (Gondwana Research)
Bird and Dinosaur Feathers
One of the co-authors of the scientific paper, Dr Benjamin Kear (Uppsala University) commented:
“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. 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”.
The Koonwarra Fish Beds Geological Reserve
The feathers come from the Koonwarra Fish Beds Geological Reserve located in South Gippsland, Victoria. The sediments represent the fine-grained clay deposits formed in a large, shallow lake. Many different fossils have been found at this location, including a fossilised flower and Ginkgo leaves. Invertebrates are well represented, the fine grained deposits preserving insects, freshwater mussels, spiders and even the remains of a horseshoe crab.
Apart from the feathers, the only evidence of vertebrates associated with this location are the remains of fish. The strata consist of alternate light and dark bands indicating an extreme seasonal environment, what you would expect in a part of the polar region where lakes would have frozen over during the extremely long winter.
A Life Reconstruction of a Theropod Dinosaur – A Likely Inhabitant of the Polar Region
Picture credit: Peter Trusler
Dinosaur Feathers Preserved as Fossils
Feather fossils from this site were first described in the 1960s but at the time they were thought to represent bird feathers, thanks to feathered dinosaur discoveries from elsewhere in the world, most notably north-eastern China, this fossil material has been reassessed and the researchers conclude that the variety of feathers at this site augments the limited skeletal evidence for a range of insulted non-avian theropods and birds living at extreme high latitudes in the southern hemisphere.
Analysis of some of the feathers has revealed residual patterning and the preservation of rod-shaped structures at the cellular level suggests the presence of eumelanosomes which in turn could help scientists determine pigments and colouration.
The scientists infer that many of the feathers indicate a dark pigmentation, such a colouration might have provided effective camouflage or permitted the absorption of a greater proportion of the energy from the rays of the sun – very useful if you inhabit a cold, dark world for much of the year.
Everything Dinosaur acknowledges the assistance of a media release from Uppsala University in the compilation of this article.
The scientific paper: “A polar dinosaur feather assemblage from Australia” by Kundrát, M., Rich, T. H., Lindgren, J., Sjövall, P., Vickers-Rich, P., Chiappe, L. M. and Kear, B. P. published in Gondwana Research.
The Everything Dinosaur website: Everything Dinosaur.