Ornithosauria

Part of speech: noun

Definitions

1. An extinct group of flying reptiles from the Mesozoic era, better known today as the pterosaurs and distinguished by their membranous wings
2. A former taxonomic order of winged archosaurs that lived during the age of dinosaurs and is now usually called pterosaurs
3. The name once given to a prehistoric order of flying reptiles whose wings were supported by a long fourth finger

Etymology: Ornithosauria is the scientific name for the group of flying reptiles often called pterosaurs. It was coined in 1842 by the English anatomist Richard Owen, who gave the group its name after examining fossil bones he thought linked birds and reptiles. The name joins two Greek words: "ornis", meaning bird, and "sauros", meaning lizard. Owen's choice reflected his belief that these creatures were reptiles with bird-like features, a view that later research has modified, since pterosaurs are now placed in their own branch of the reptile family tree. The Greek roots show how the name was built from classical parts, not drawn from any ancient description. Ancient Greeks had no word for these animals as a group, and the fossils were only identified in the early nineteenth century. Owen's coinage thus combined two old Greek words to name a creature that had lived more than 200 million years earlier.