Sinornis santensis

Sinornis santensis was a fossil bird from the Early Cretaceous period, approximately 135 million years ago. This crow-sized bird, discovered from remains sent to paleontologist Paul Sereno by a Chinese colleague, is considered among the earliest birds capable of sustained flight.1

Confuciusornis, another genus of extinct bird from the Late Jurassic and Early Cretaceous, also lived in ancient China. Fossils indicate it was about 25 cm long, with a small, toothless snout. While possessing some modern bird characteristics, Confuciusornis retained three free fingers on its hand, similar to theropod dinosaurs.2

Feathers, now understood to have evolved before birds and flight, likely served functions such as insulation or communication in early theropod dinosaurs. The discovery of feathered dinosaurs like Sinosauropteryx has provided significant insight into the evolution of birds from their dinosaur ancestors.34