In 1861, scientists discovered Archaeopteryx, a dinosaur with feathers, in 150-million-year-old limestones in Solnhofen, Germany. They didn’t know it at the time, but that fossilized skeleton — and the several that followed — provided a key piece of evidence for the theory of evolution, as well as for the fact that birds were actually dinosaurs.

Archaeopteryx specimens have, “maybe more than any other fossil, changed the way that we see the world,” said Jingmai O’Connor, a paleontologist at the Field Museum in Chicago.

Over 164 years, researchers have pored over every detail of available specimens, trying to puzzle out how birds came to fly. Therefore, you might expect that such a well-studied fossil species wouldn’t be capable of surprises. But ina paper published on Wednesday in the journal Nature, Dr. O’Connor and a team of researchers revealed previously unrecorded soft tissues and skeletal details from a new specimen, known as the Chicago Archaeopteryx. What they found also helps explain why some feathered dinosaurs got off the ground, if only for short-haul flights.

Sussing out Archaeopteryx’s abilities in flight and how it fit in its environment has long been tricky, Dr. O’Connor said. A majority of specimens are cartoonishly flattened by geology, making it difficult to discern important skeletal details. And while its earliest discoverers and most modern scientists have concluded that the species could likely take off, particular bodily features have left paleontologists seeking more data.

The latest specimen, acquired by the Field Museum in 2022 and on public display since 2024, allowed Dr. O’Connor’s team to begin addressing some of the anatomical uncertainties.