Nav: Home

The early bird got to fly: Archaeopteryx was an active flyer

March 13, 2018

The question of whether the Late Jurassic dino-bird Archaeopteryx was an elaborately feathered ground dweller, a glider, or an active flyer has fascinated palaeontologists for decades. Valuable new information obtained with state-of-the-art synchrotron microtomography at the ESRF, the European Synchrotron (Grenoble, France), allowed an international team of scientists to answer this question in Nature Communications. The wing bones of Archaeopteryx were shaped for incidental active flight, but not for the advanced style of flying mastered by today's birds.

Was Archaeopteryx capable of flying, and if so, how? Although it is common knowledge that modern-day birds descended from extinct dinosaurs, many questions on their early evolution and the development of avian flight remain unanswered. Traditional research methods have thus far been unable to answer the question whether Archaeopteryx flew or not. Using synchrotron microtomography at the ESRF's beamline ID19 to probe inside Archaeopteryx fossils, an international team of scientists from the ESRF, Palacký University, Czech Republic, CNRS and Sorbonne University, France, Uppsala University, Sweden, and Bürgermeister-Müller-Museum Solnhofen, Germany, shed new light on this earliest of birds.

Reconstructing extinct behaviour poses substantial challenges for palaeontologists, especially when it comes to enigmatic animals such as the famous Archaeopteryx from the Late Jurassic sediments of southeastern Germany that is considered the oldest potentially free-flying dinosaur. This well-preserved fossil taxon shows a mosaic anatomy that illustrates the close family relations between extinct raptorial dinosaurs and living dinosaurs: the birds. Most modern bird skeletons are highly specialised for powered flight, yet many of their characteristic adaptations in particularly the shoulder are absent in the Bavarian fossils of Archaeopteryx. Although its feathered wings resemble those of modern birds flying overhead every day, the primitive shoulder structure is incompatible with the modern avian wing beat cycle.

"The cross-sectional architecture of limb bones is strongly influenced by evolutionary adaptation towards optimal strength at minimal mass, and functional adaptation to the forces experienced during life", explains Prof. Jorge Cubo of the Sorbonne University in Paris. "By statistically comparing the bones of living animals that engage in observable habits with those of cryptic fossils, it is possible to bring new information into an old discussion", says senior author Dr. Sophie Sanchez from Uppsala University, Sweden

Archaeopteryx skeletons are preserved in and on limestone slabs that reveal only part of their morphology. Since these fossils are among the most valuable in the world, invasive probing to reveal obscured or internal structures is therefore highly discouraged. "Fortunately, today it is no longer necessary to damage precious fossils", states Dr. Paul Tafforeau, beamline scientist at the ESRF. "The exceptional sensitivity of X-ray imaging techniques for investigating large specimens that is available at the ESRF offers harmless microscopic insight into fossil bones and allows virtual 3D reconstructions of extraordinary quality. Exciting upgrades are underway, including a substantial improvement of the properties of our synchrotron source and a brand new beamline designated for tomography. These developments promise to give even better results on much larger specimens in the future".

Scanning data unexpectedly revealed that the wing bones of Archaeopteryx, contrary to its shoulder girdle, shared important adaptations with those of modern flying birds. "We focused on the middle part of the arm bones because we knew those sections contain clear flight-related signals in birds", says Dr. Emmanuel de Margerie, CNRS, France. "We immediately noticed that the bone walls of Archaeopteryx were much thinner than those of earthbound dinosaurs but looked a lot like conventional bird bones", continues lead author Dennis Voeten of the ESRF. "Data analysis furthermore demonstrated that the bones of Archaeopteryx plot closest to those of birds like pheasants that occasionally use active flight to cross barriers or dodge predators, but not to those of gliding and soaring forms such as many birds of prey and some seabirds that are optimised for enduring flight."

"We know that the region around Solnhofen in southeastern Germany was a tropical archipelago, and such an environment appears highly suitable for island hopping or escape flight", remarks Dr. Martin Röper, Archaeopteryx curator and co-author of the report. "Archaeopteryx shared the Jurassic skies with primitive pterosaurs that would ultimately evolve into the gigantic pterosaurs of the Cretaceous. We found similar differences in wing bone geometry between primitive and advanced pterosaurs as those between actively flying and soaring birds", adds Vincent Beyrand of the ESRF.

Since Archaeopteryx represents the oldest known flying member of the avialan lineage that also includes modern birds, these findings not only illustrate aspects of the lifestyle of Archaeopteryx but also provide insight into the early evolution of dinosaurian flight. "Indeed, we now know that Archaeopteryx was already actively flying around 150 million years ago, which implies that active dinosaurian flight had evolved even earlier!" says Prof. Stanislav Bureš of Palacký University in Olomouc. "However, because Archaeopteryx lacked the pectoral adaptations to fly like modern birds, the way it achieved powered flight must also have been different. We will need to return to the fossils to answer the question on exactly how this Bavarian icon of evolution used its wings", concludes Voeten.

It is now clear that Archaeopteryx is a representative of the first wave of dinosaurian flight strategies that eventually went extinct, leaving only the modern avian flight stroke directly observable today.
-end-


European Synchrotron Radiation Facility

Related Fossils Articles:

Tiny fossils reveal backstory of the most mysterious amphibian alive
Researchers have determined that the fossils of an extinct species from the Triassic Period are the long-missing link that connects Kermit the Frog's amphibian brethren to wormlike creatures with a backbone and two rows of sharp teeth.
Moroccan fossils show human ancestors' diet of game
New fossil finds from the Jebel Irhoud archaeological site in Morocco do more than push back the origins of our species by 100,000 years.
South African cave yields yet more fossils of a newfound relative
Probing deeper into the South African cave system known as Rising Star, which last year yielded the largest cache of hominin fossils known to science, an international team of researchers has discovered another chamber with more remains of a newfound human relative, Homo naledi.
Research sheds new light on 'world's oldest animal fossils'
A team of researchers, led by the University of Bristol, has uncovered that ancient fossils, thought to be some of the world's earliest examples of animal remains, could in fact belong to other groups such as algae.
Viral fossils reveal how our ancestors may have eliminated an ancient infection
Scientists have uncovered how our ancestors may have wiped out an ancient retrovirus around 11 million years ago.
World's oldest plant-like fossils discovered
Scientists at the Swedish Museum of Natural History have found fossils of 1.6 billion-year-old probable red algae.
World's oldest fossils unearthed
Remains of microorganisms at least 3,770 million years old have been discovered by an international team led by UCL scientists, providing direct evidence of one of the oldest life forms on Earth.
New study gives weight to Darwin's theory of 'living fossils'
A team of researchers from the University of Bristol studying the 'living fossil' Sphenodon -- or tuatara -- have identified a new way to measure the evolutionary rate of these enigmatic creatures, giving credence to Darwin's theory of 'living fossils.'
Fossils found reveal unseen 'footprint' maker
Fossils found in Morocco from the long-extinct group of sea creatures called trilobites, including rarely seen soft-body parts, may be previously unseen animals that left distinctive fossil 'footprints' around the ancient supercontinent Gondwana.
The best way to include fossils in the 'tree of life'
A team of scientists from the University of Bristol has suggested that we need to use a fresh approach to analyze relationships in the fossil record to show how all living and extinct species are related in the 'tree of life.'

Related Fossils Reading:

Smithsonian Handbooks: Fossils
by David Ward (Author)

National Audubon Society Field Guide to North American Fossils
by Ida Thompson (Author), Townsend P. Dickinson (Photographer)

The World Encyclopedia of Fossils & Fossil-Collecting:: An Illustrated Reference Guide To Over 375 Plant And Animal Fossils From Around The Globe And ... Them, With Over 950 Photographs And Artworks
by Steve Parker (Author)

Fossils: A Fully Illustrated, Authoritative and Easy-to-Use Guide (A Golden Guide from St. Martin's Press)
by Frank H. T. Rhodes (Author), Paul R. Shaffer (Author), Herbert S. Zim (Author), Raymond Perlman (Illustrator)

Curious About Fossils (Smithsonian)
by Kate Waters (Author)

Discover Science: Rocks and Fossils
by Chris Pellant (Author)

101 American Fossil Sites You've Gotta See
by Albert B Dickas (Author)

Fossils (True Books)
by Ann O. Squire (Author)

Fossil
by Bill Thomson (Author), Bill Thomson (Illustrator)

Fossils Tell of Long Ago (Let's-Read-and-Find-Out Science 2)
by Aliki (Author), Aliki (Illustrator)

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Dying Well
Is there a way to talk about death candidly, without fear ... and even with humor? How can we best prepare for it with those we love? This hour, TED speakers explore the beauty of life ... and death. Guests include lawyer Jason Rosenthal, humorist Emily Levine, banker and travel blogger Michelle Knox, mortician Caitlin Doughty, and entrepreneur Lux Narayan.
Now Playing: Science for the People

#491 Frankenstein LIVES
Two hundred years ago, Mary Shelley gave us a legendary monster, shaping science fiction for good. Thanks to her, the name of Frankenstein is now famous world-wide. But who was the real monster here? The creation? Or the scientist that put him together? Tune in to a live show from Dragon Con 2018 in Atlanta, as we breakdown the science of Frankenstein, complete with grave robbing and rivers of maggots. Featuring Tina Saey, Lucas Hernandez, Travor Valle, and Nancy Miorelli. Moderated by our own Bethany Brookshire. Related links: Scientists successfully transplant lab-grown lungs into pigs, by Maria Temming on Science...