Cruralispennia

Cruralispennia had a plough-shaped pygostyle, a fused tail bone that was thought to only exist in more advanced birds. This shows that different bird groups evolved similar features separately.1

Its leg feathers were unlike any seen before: the base was like a stiff wire, and the tip was fluffy and split into many tiny strands.1

Even though Cruralispennia lived very early in bird history, its shoulder bone (coracoid) was already very slender, a shape usually found in later Cretaceous birds.1

The name Cruralispennia means 'leg feather' in Latin, because of the unusual feathers on its shin bone (tibiotarsus).1

This bird had 14 teeth in its lower jaw, which is why its full species name is multidonta, meaning 'many teeth'.1

Cruralispennia lived alongside other early birds like Protopteryx and Eoconfuciusornis in the same ancient lake environment.1