Landscape with Captorhinus life reconstruction.
Artwork by Michael deBraga.
Today’s casual refutation of creationism comes from a team of palaeontologists who have examined an extraordinary, mummified fossil and uncovered yet another piece of evidence that creationist dogma says should not exist. Their findings have now been published in Nature.
The fossil, an early amniote reptile, Captorhinus aguti, is awkward for creationists on several counts. To begin with, it is about 289–286 million years old — vastly older than their mythology permits, and far beyond anything that can be hand-waved away as a dating “margin of error”. But it is even more troublesome than that, because it preserves evidence of a crucial evolutionary innovation: an early rib-assisted breathing apparatus for ventilating the lungs, helping to free vertebrates from the more limited breathing methods of their amphibian relatives and allowing them to thrive fully on land.
That innovation was a major step in the evolution of terrestrial tetrapods. Costal breathing — using the ribcage and associated muscles to expand and compress the chest — provided a far more efficient way of moving air in and out of the lungs. It helped set amniotes on the path to a more active life on land, in drier environments, and ultimately to the huge evolutionary success of reptiles, birds and mammals.
The remains are remarkable for the level of preservation. The fossil retains not only the skeleton, but also three-dimensional skin, preserved cartilages and even ancient protein remnants. Most importantly, it preserves elements of the thoracic apparatus involved in costal breathing, including structures linking the ribcage, sternum and shoulder girdle. These fossils come from the Richards Spur cave deposits in Oklahoma, already famous for yielding one of the most diverse known vertebrate assemblages from the Early Permian.
To study the fossils without damaging them, the team used high-resolution neutron computed tomography, allowing them to look beneath the surface of three specimens non-destructively. What they found sheds new light on how the amniote breathing apparatus evolved and helps document one of the key anatomical changes that made vertebrate life on land so successful.
Richards Spur^ An Early Permian Fossil Treasure House. Located in Oklahoma, in the Dolese Brothers limestone quarry near Lawton, Richards Spur is one of the most important Early Permian vertebrate fossil localities in the world, dating to about 289–286 million years ago.That significance is explained in a news release from Harvard’s Department of Organismic and Evolutionary Biology:
What makes the site so remarkable is the sheer diversity and quality of its fossils. Since its discovery in 1932, it has produced tens of thousands of specimens, representing more than 40 species of early land vertebrates, including reptiles, synapsids and amphibian-like tetrapods. It is therefore one of the richest windows we have into life on land during the Early Permian.
Unlike many fossil sites formed in rivers or lake beds, Richards Spur consists of ancient cave and fissure fillings in much older limestone. Animals and their remains were washed or fell into these caves, where they were rapidly buried. This unusual setting helped preserve fossils in extraordinary detail, sometimes including delicate skin impressions, soft tissues and other structures that are rarely fossilised.
That is why Richards Spur is so important to palaeontology. It does not merely provide isolated bones, but an unusually detailed picture of an entire terrestrial ecosystem at a crucial stage in vertebrate evolution, when early amniotes were becoming fully adapted to life on land.
The Oldest Breath: A 300-Million-Year-Old Mummy Reveals the Origins of How Amniotes Breathe
Every breath you take is an ancient inheritance. The rise and fall of your chest, the intercostal muscles pulling your ribs outward, the rush of air into your lungs — this mechanism is so familiar it barely registers as remarkable. But a tiny, mummified reptile that died in an Oklahoma cave roughly 289 million years ago has revealed the oldest example of this breathing system in amniotes – a group that includes all reptiles, birds, mammals, and their common ancestors, among the first to conquer life on land.
In a new study published in Nature, researchers describe the extraordinary preservation of the oldest known costal breathing system in Captorhinus aguti, a small, lizard-like creature from the early Permian period. The mummified fossil, which is only a few inches long, preserves not only bones, but also three-dimensional skin, calcified cartilage, and — most astonishingly — protein remnants that predate the previous oldest-known example by nearly 100 million years.
Captorhinus is an interesting lizard-looking critter that is critical to understanding early amniote evolution.
Ethan D. Mooney, co-lead author
Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology
Harvard University
Cambridge, MA, USA.
[Ethan D. Mooney was] a student at the University of Toronto in co-author Professor Robert Reisz’s lab and is now a PhD candidate in the Department of Organismic and Evolutionary Biology at Harvard University, where he works with paleontologist Professor Stephanie Pierce. These creatures, which ranged in size from five centimeters to a few feet, were among the earliest known reptiles to experiment with living on land. During their time, they were thriving and numerous.
Captorhinus was discovered in the unique cave systems near Richards Spur, Oklahoma, a site so rich in late Paleozoic life that it holds the most diverse terrestrial vertebrate assemblage known from that era – a time already famous for producing the most species-rich terrestrial vertebrates. The site’s unique conditions, including oil-seep hydrocarbons and oxygen-free mud, preserved not only the animal’s bones, but also its skin and cartilage, resulting in a three dimensional mummified fossil frozen in its death pose, with its arm tucked beneath its body.
289-million-year-old reptile Captorhinus in its death pose in a cave system. Oil seepages, hyper-mineralized water, fine clays in this cave made it an ideal environment for mummification and fossilization of soft tissues like skin, cartilage, and protein remnants.Artwork by Dr. Michael DeBraga.
Using neutron computed tomography (nCT) at a specialized facility in Australia, the team was able to peer beneath the rock without disturbing the fossil. What Mooney found while processing the scans stunned him.
I started to see all these structures wrapped around the bones, they were very thin and textured. And lo and behold, there was a nice wrapping of skin around the torso of this animal. The scaly skin has this wonderful accordion-like texture, with these concentric bands covering much of the body from the torso and up to the neck.
Ethan D. Mooney.
The pattern resembles the scales of modern worm lizards — small, burrowing reptiles alive today.
But the skin was only part of the story. The team studied three Captorhinus specimens from Richards Spur that, together, told a story about breathing. In one specimen, they identified a segmented cartilaginous sternum, sternal ribs, intermediate ribs, and structures connecting the ribcage to the shoulder girdle. For the first time in the fossil record, it was possible to view these structures in an early reptile and reconstruct the complete breathing apparatus of an early amniote.
Before amniotes evolved this system, the dominant strategy belonged to amphibians — breathing through their skin and pumping air through their lungs using their mouths and throats; strategies that modern amphibians still largely rely on today, but aren’t well suited for the more active lifestyles of amniotes. Costal aspiration breathing, in which the muscles between the ribs expand and compress the chest cavity to draw air deep into the lungs, is far more powerful, bringing more oxygen in and more carbon dioxide out.
We propose that the system found in Captorhinus represents the ancestral condition for the kind of rib assisted respiration present in living reptiles, birds, and mammals.
Professor Robert Reisz, co-lead author.
Department of Biology
University of Toronto Mississauga
Mississauga, Ontario, Canada.
Using ribcage musculature was an evolutionary innovation fundamental to the conquest of the terrestrial realm by these earliest ancestors of modern reptiles and mammals. This system likely also contributed to the explosive diversification of early amniotes, setting the stage for their dominance on land.
It was a game changer that allowed these animals to adopt a much more active lifestyle.
Ethan D. Mooney.
The find also revealed an unexpected bonus. Chemical analysis using synchrotron infrared spectroscopy detected remnants of original proteins preserved in the bone, cartilage, and skin. These organic molecules, never before seen in fossils from the Paleozoic era, are nearly 100 million years older than the previous oldest example, which was found in a dinosaur.
The protein remnant finding is exceptional, it dramatically pushes our understanding of what is possible in terms of soft tissue preservation in the fossil record.
Ethan D. Mooney.
The fossils are now housed in the Royal Ontario Museum in Toronto, where they are available for future study. Meanwhile, Mooney has brought his expertise in early reptiles to Harvard, where he continues to explore the evolutionary mysteries of early reptiles, advancing our understanding of how these creatures helped shape the world we live in today.
Publication:
What makes this discovery so awkward for creationism is not merely the age of the fossil, although that alone is enough to demolish the childish notion that Earth and all its life were conjured into existence a few thousand years ago. It is that the fossil shows an evolutionary transition in progress: not a fully formed creature appearing by magic, but an early amniote preserving anatomical evidence of one of the key innovations that allowed vertebrates to become truly independent of water and conquer dry land.
That is how science works. It does not begin with an unchallengeable conclusion and then twist the facts to fit it. It follows the evidence wherever it leads, even when that evidence comes from a 300-million-year-old animal entombed in an Oklahoma cave deposit and examined with technology undreamed of even a few decades ago. Each new discovery adds detail to the picture, not by appealing to myth, but by testing ideas against reality.
Creationism, by contrast, has nothing useful to say about why this fossil exists, why it is found in rocks of exactly the age geology predicts, why it preserves transitional anatomy exactly where evolution says it should, or why independent methods from palaeontology, stratigraphy, physics and comparative anatomy all converge on the same answer. It can only deny, evade or misrepresent. Science explains.
And that is why fossils like Captorhinus aguti matter. They are not just curious relics from a vanished world; they are hard evidence that life has a deep history, that major biological innovations evolved step by step, and that the story of life on Earth is written in stone for anyone honest enough to read it.
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