Pterosaurs remained relatively small through the Jurassic and only evolved much larger body sizes in the Cretaceous.

Pterosaurs eventually produced the largest flying animals known, with some Cretaceous species reaching enormous wingspans. Older reconstructions placed most of that increase late in their history. Triassic and Jurassic pterosaurs were generally pictured as relatively small, with a major rise in body size near the end of the Jurassic or in the Cretaceous.

The fossil record from the Middle Jurassic is poor, which made that pattern difficult to test.

In 2022, researchers described Dearc sgiathanach from the Isle of Skye in Scotland. The three-dimensional skeleton belonged to an animal with an estimated wingspan greater than about 2.5 metres. Bone histology showed that it was still growing when it died.

The team also revisited fragmentary Middle Jurassic fossils from England and found evidence that other pterosaurs could reach comparable sizes. The scarcity of complete fossils had hidden part of the size range.

The Cretaceous still saw much larger forms and a broader trend toward gigantism. But large pterosaurs were no longer something that appeared only late in the group’s evolution; substantial body size had already evolved by the Middle Jurassic.