Chicago museum's fossil yields insights on famed early bird Archaeopteryx
A new analysis of a pigeon-sized Archaeopteryx fossil in the collection of the Field Museum in Chicago is revealing an array of previously unknown features of the earliest-known bird, providing insight into its feathers, hands, feet and head.
The specimen, unearthed in southern Germany, is one of the most complete and best preserved of the 14 known fossils of Archaeopteryx identified since 1861. The discovery of the first Archaeopteryx fossil, with its blend of reptile-like and bird-like features, caused a sensation, lending support to British naturalist Charles Darwin's ideas about evolution and showing that birds had descended from dinosaurs.
The new study, examining the Chicago fossil using UV light to make out soft tissues and CT scans to discern minute details still embedded in the rock, shows that 164 years later there is more to learn about this celebrated creature that took flight 150 million years ago during the Jurassic Period.
The researchers identified anatomical traits indicating that while Archaeopteryx was capable of flight, it probably spent a lot of time on the ground and may have been able to climb trees.
The scientists identified for the first time in an Archaeopteryx fossil the presence of specialized feathers called tertials on both wings. These innermost flight feathers of the wing are attached to the elongated humerus bone in the upper arm. Birds evolved from small feathered dinosaurs, which lacked tertials. The discovery of them in Archaeopteryx, according to the researchers, suggests that tertials, present in many birds today, evolved specifically for flight.
Feathered dinosaurs lacking tertials would have had a gap between the feathered surface of their upper arms and the body.
"To generate lift, the aerodynamic surface must be continuous with the body. So in order for flight using feathered wings to evolve, dinosaurs had to fill this gap — as we see in Archaeopteryx," said Field Museum paleontologist Jingmai O'Connor, lead author of the study published on Wednesday in the journal Nature.
"Although we have studied Archaeopteryx for over 160 years, so much basic information is still controversial. Is it a bird? Could it fly? The presence of tertials supports the interpretation that the answer to both these questions is 'yes,'" O'Connor added.
The delicate specimen, preserved in three dimensions rather than squashed flat like many fossils, was painstakingly prepared to protect soft tissue remains, which glowed under ultraviolet light.
Birds are the only members of the dinosaur lineage to have survived a mass extinction 66 million years ago, caused by an asteroid striking Earth. Archaeopteryx boasted reptilian traits like teeth, a long and bony tail, and claws on its hands, alongside bird-like traits like wings formed by large, asymmetrical feathers.
The soft tissue of its toe pads appears to have been adapted for spending a lot of its life on the ground, consistent with the limited flight capabilities that Archaeopteryx is believed to have possessed.
"That's not to say it couldn't perch. It could do so still pretty well. But the point being that near the beginning of powered flight, Archaeopteryx was still spending most of its time on the ground," said study co-author Alex Clark, a doctoral student in evolutionary biology at the University of Chicago and the Field Museum.
The soft tissue on the hand suggests that the first and third fingers were mobile and could be used for climbing.
An examination of Archaeopteryx's palate — roof of the mouth — confirmed that its skull was immobile, unlike many living birds. But there was skeletal evidence of the first stages in the evolution of a trait that lets the beak move independently from the braincase, as seen in modern birds.
The fossil possesses the only complete Archaeopteryx vertebral column, including two tiny vertebrae at the tip of the tail showing it had 24 vertebrae, one more than previously thought.
The museum last year announced the acquisition of the fossil, which it said had been in the hands of a series of private collectors since being unearthed sometime before 1990.
"This specimen is arguably the best Archaeopteryx ever found and we're learning a ton of new things from it," O'Connor said.
"I consider Archaeopteryx to be the most important fossil species of all time. It is, after all, the icon of evolution, and evolution is the unifying concept of the biological sciences. Not only is Archaeopteryx the oldest-known fossil bird, with birds today being the most successful lineage of land vertebrates, it is the species that demonstrates that birds are living dinosaurs," O'Connor said. (Reuters)
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Korea Herald
23-05-2025
- Korea Herald
Lethal mutations in pregnancy loss
REYKJAVIK, Iceland, May 21, 2025 /PRNewswire/ -- In a study published in Nature today "Sequence diversity lost in early pregnancy," scientists from deCODE genetics, a subsidiary of Amgen, estimate that around one in 136 pregnancies are lost due to new mutations in the fetus. In other words, millions of pregnancies worldwide are lost because of mutations every year. The human genome varies between individuals, but there are some locations in the genome where there seems to be little or no sequence variation between individuals. This raises the question whether the sequences at these locations are essential for human development? It is known that mutations in essential genomic sequences are major contributors to neurodevelopmental disorders, the question remains, do they also contribute to pregnancy loss? As part of a Nordic collaboration, scientists from deCODE genetics sought to answer these questions by sequencing 467 samples from pregnancy losses from a prospective study initiated by Henriette Svarre Nielsen and Eva R. Hoffmann. Interestingly, by comparing the genomes of the fetuses from pregnancy losses to their parents the scientists found that the fetuses harbored a similar number of new mutations as adults. "Despite the similar numbers, we discovered that the main difference between the lost fetuses and adults was that the mutations in the fetuses occurred in essential genomic sequences," says Hákon Jónsson scientist at deCODE genetics, and one of the authors on the paper. Moreover, they managed to pinpoint when, in the development of the fetus, some of the mutations occurred. In addition to mapping new mutations in the lost fetuses, they also showed that some couples are at a higher risk of pregnancy loss due to genetic compatibility issues. You inherit one copy of a gene from each parent, and most of the time, you are fine with one defective copy, but problems can arise if you inherit a defective copy from both parents. "We have shown previously that for certain genes, you never observe two defective copies in adult genomes, but we found two defective copies in some of the pregnancy losses. Importantly, these involve a high risk for recurrence of pregnancy loss for the couple but can be selected against in IVF treatments," says Guðný A. Árnadóttir scientist at deCODE genetics, and one of the authors on the paper. Along with recombination, the continuous generation of mutations enables us to evolve as a species. However, this continuous influx of new mutations comes at the expense of rare diseases. This study demonstrates the contribution of mutations to pregnancy loss and sheds new light on conserved sequences in the human genome. Based in Reykjavik, Iceland, deCODE genetics is a global leader in analyzing and understanding the human genome. Using its unique expertise and population resources, deCODE has discovered genetic risk factors for dozens of common diseases. The purpose of understanding the genetics of disease is to use that information to create new means of diagnosing, treating and preventing disease. deCODE genetics is a wholly-owned subsidiary of Amgen.
Korea Herald
22-05-2025
- Korea Herald
Two Galaxies in 'joust' before mega-merger
WASHINGTON (Reuters) — Astronomers have observed two distant galaxies — both possessing roughly as many stars as our Milky Way — careening toward each other before their inevitable merger at a time when the universe was about a fifth its current age, a scene resembling two knights charging in a joust. The galaxies, observed using two Chile-based telescopes, were seen as they existed about 11.4 billion years ago, approximately 2.4 billion years after the Big Bang event that initiated the universe. At the heart of one of the galaxies resides a quasar, a highly luminous object powered by gas and other material falling into a supermassive black hole. The intense radiation across the electromagnetic spectrum unleashed by the quasar is seen disrupting clouds of gas and dust, known as molecular clouds, in the other galaxy. It is molecular clouds that give rise to stars. But the effects of the quasar's radiation turned the clouds in the affected region into "only tiny dense cloudlets that are too small to form stars," said astrophysicist Sergei Balashev of the Ioffe Institute in Saint Petersburg, Russia, co-lead author of the study published on Wednesday in the journal Nature. This is the first time such a phenomenon has been observed, Balashev said. Stars form by the slow contraction under gravity of these clouds, with small centers taking shape that heat up and become new stars. But the galaxy affected by the quasar's radiation was left with fewer regions that could serve as such stellar nurseries, undermining its star formation rate. The interaction between the two galaxies reminded the researchers of a medieval joust. "Much like jousting knights charging toward one another, these galaxies are rapidly approaching. One of them — the quasar host — emits a powerful beam of radiation that pierces the companion galaxy, like a lance. This radiation 'wounds' its 'opponent' as it disrupts the gas," said astronomer and co-lead author Pasquier Noterdaeme of the Paris Institute of Astrophysics in France. Supermassive black holes are found at the heart of many galaxies, including the Milky Way. The researchers estimated the mass of the one that serves as the engine of the quasar studied in this research at about 200 million times that of our sun. The intense gravitational strength of the supermassive black hole pulls gas and other material toward it. As this stuff spirals inward at high speed, it heats up due to friction, forming a disk that emits extremely powerful radiation in two opposite directions, called biconical beams. The ultraviolet light from one of these beams is what played havoc with the gas in the companion galaxy. This supermassive black hole is much more massive than the one at the center of the Milky Way — called Sagittarius A*, or Sgr A* — which possesses roughly 4 million times the mass of the sun and is located about 26,000 light-years from Earth. A light-year is the distance light travels in a year, 9.5 trillion kilometers. The researchers used the Atacama Large Millimeter/submillimeter Array, or ALMA, to characterize the two galaxies and used the European Southern Observatory's Very Large Telescope, or VLT, to probe the quasar as well as the gas in the companion galaxy. The configuration of the galaxies as viewed from the perspective of Earth enabled the researchers to observe the radiation from the quasar passing directly through the companion galaxy. Most galactic mergers that have been observed by astronomers occurred later in the history of the universe. "Galaxies are typically found in groups, and gravitational interactions naturally lead to mergers over cosmic time," Noterdaeme said. "In line with current understanding, these two galaxies will eventually coalesce into a single larger galaxy. The quasar will fade as it exhausts the available fuel."
Korea Herald
15-05-2025
- Korea Herald
Chicago museum's fossil yields insights on famed early bird Archaeopteryx
A new analysis of a pigeon-sized Archaeopteryx fossil in the collection of the Field Museum in Chicago is revealing an array of previously unknown features of the earliest-known bird, providing insight into its feathers, hands, feet and head. The specimen, unearthed in southern Germany, is one of the most complete and best preserved of the 14 known fossils of Archaeopteryx identified since 1861. The discovery of the first Archaeopteryx fossil, with its blend of reptile-like and bird-like features, caused a sensation, lending support to British naturalist Charles Darwin's ideas about evolution and showing that birds had descended from dinosaurs. The new study, examining the Chicago fossil using UV light to make out soft tissues and CT scans to discern minute details still embedded in the rock, shows that 164 years later there is more to learn about this celebrated creature that took flight 150 million years ago during the Jurassic Period. The researchers identified anatomical traits indicating that while Archaeopteryx was capable of flight, it probably spent a lot of time on the ground and may have been able to climb trees. The scientists identified for the first time in an Archaeopteryx fossil the presence of specialized feathers called tertials on both wings. These innermost flight feathers of the wing are attached to the elongated humerus bone in the upper arm. Birds evolved from small feathered dinosaurs, which lacked tertials. The discovery of them in Archaeopteryx, according to the researchers, suggests that tertials, present in many birds today, evolved specifically for flight. Feathered dinosaurs lacking tertials would have had a gap between the feathered surface of their upper arms and the body. "To generate lift, the aerodynamic surface must be continuous with the body. So in order for flight using feathered wings to evolve, dinosaurs had to fill this gap — as we see in Archaeopteryx," said Field Museum paleontologist Jingmai O'Connor, lead author of the study published on Wednesday in the journal Nature. "Although we have studied Archaeopteryx for over 160 years, so much basic information is still controversial. Is it a bird? Could it fly? The presence of tertials supports the interpretation that the answer to both these questions is 'yes,'" O'Connor added. The delicate specimen, preserved in three dimensions rather than squashed flat like many fossils, was painstakingly prepared to protect soft tissue remains, which glowed under ultraviolet light. Birds are the only members of the dinosaur lineage to have survived a mass extinction 66 million years ago, caused by an asteroid striking Earth. Archaeopteryx boasted reptilian traits like teeth, a long and bony tail, and claws on its hands, alongside bird-like traits like wings formed by large, asymmetrical feathers. The soft tissue of its toe pads appears to have been adapted for spending a lot of its life on the ground, consistent with the limited flight capabilities that Archaeopteryx is believed to have possessed. "That's not to say it couldn't perch. It could do so still pretty well. But the point being that near the beginning of powered flight, Archaeopteryx was still spending most of its time on the ground," said study co-author Alex Clark, a doctoral student in evolutionary biology at the University of Chicago and the Field Museum. The soft tissue on the hand suggests that the first and third fingers were mobile and could be used for climbing. An examination of Archaeopteryx's palate — roof of the mouth — confirmed that its skull was immobile, unlike many living birds. But there was skeletal evidence of the first stages in the evolution of a trait that lets the beak move independently from the braincase, as seen in modern birds. The fossil possesses the only complete Archaeopteryx vertebral column, including two tiny vertebrae at the tip of the tail showing it had 24 vertebrae, one more than previously thought. The museum last year announced the acquisition of the fossil, which it said had been in the hands of a series of private collectors since being unearthed sometime before 1990. "This specimen is arguably the best Archaeopteryx ever found and we're learning a ton of new things from it," O'Connor said. "I consider Archaeopteryx to be the most important fossil species of all time. It is, after all, the icon of evolution, and evolution is the unifying concept of the biological sciences. Not only is Archaeopteryx the oldest-known fossil bird, with birds today being the most successful lineage of land vertebrates, it is the species that demonstrates that birds are living dinosaurs," O'Connor said. (Reuters)
