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What this article is about

This summary covers The Economist’s April 11th, 2026 Science & technology article listed in the contents as The evolution of breathing and published under the headline This calls for bubbles.

The article explains a seemingly obscure but important evolutionary shift: how animals moved from the cheek-based breathing used by amphibians to the rib-assisted breathing used by reptiles and mammals. A new paper in Nature, based on unusually well-preserved fossil reptiles, suggests that this transition happened at roughly the same time vertebrates were learning to walk properly on dry land, at least 290m years ago.

The broader point is that breathing was not just a background biological detail. It was part of the package that made life on land more viable and ultimately made reptiles far more adaptable than their amphibian ancestors.

Why the change mattered

The article starts by setting out the biological contrast. Fish move oxygen-rich water over gills. Amphibians push air or water into their lungs using their cheeks. Reptiles and mammals instead rely on muscles associated with the ribs and shoulders to expand and contract the chest cavity. That method is much closer to the breathing system familiar in humans.

According to the article, rib-assisted breathing was a major upgrade. Cheek-breathing constrains the anatomy of the head and neck, which limits how much body plans can diversify. It is also a less efficient way to move air. Amphibians partly compensate through their permeable skin, which can top up oxygen when they are out of water, but that is not a robust long-term solution for active animals on land.

Rib-assisted breathing, by contrast, gave early reptiles a more effective way to oxygenate their bodies while also freeing them from some of the anatomical restrictions faced by amphibians. In The Economist’s telling, this was one reason reptiles went on to diversify quickly and, much later, dominate the planet in the form of dinosaurs for more than 100m years.

How the evidence was found

The article’s core scientific claim rests on a preservation fluke. The soft tissues relevant to breathing, including cartilage and muscles, usually decay too quickly to leave clear fossil evidence. That has long made it difficult to work out when rib-assisted breathing first appeared.

The breakthrough came from fossils found near Richards Spur, Oklahoma. The cave environment there was unusually good at preserving bodies: petroleum discouraged bacteria, the area was dry enough to mummify remains, and fine sediment accumulated quickly enough to shield them from oxygen. Two fossils of the extinct reptile genus Captorhinus survived in exactly those conditions.

Using CT scans, the researchers were able to detect a flexible cartilage sternum and the structural relationship between the ribs, rib muscles and shoulder girdle. That combination indicates a chest-based breathing system much like the one used by modern lizards. The article presents this as the clearest evidence yet that the rib-assisted mechanism had already evolved in very early reptiles.

Why palaeontologists care

The most interesting implication is not just that scientists now have an earlier date for this respiratory shift. It is that breathing and movement appear to have evolved together. The shoulder girdle in these ancient reptiles was doing double duty: helping support the body on land while also participating in the mechanics of ventilation.

That supports a long-standing hypothesis that the move onto land required a coordinated redesign, not a sequence of isolated upgrades. Better walking and better breathing were likely intertwined. The article is careful not to overclaim: it says the new fossil evidence does not settle whether improved movement came first and breathing adapted to it, or whether the breathing system changed first and enabled more capable locomotion. But it does make the coupling between the two look much more plausible.

The takeaway

The article’s main achievement is to turn an abstract evolutionary mystery into a concrete story anchored in rare fossils. By showing that an ancient reptile already had the chest-and-rib mechanics associated with modern land animals, the new research helps explain how vertebrates made the jump from limited amphibian-style breathing to the more powerful system that underpins reptile and mammal life today.

In plain English: The Economist argues that one of the keys to conquering land was learning not just how to walk there, but how to breathe there efficiently. That link between locomotion and respiration may have been in place far earlier than scientists could previously prove.