The fossil record shows that [[1]] are feathered dinosaurs.

Birds are descended from theropod dinosaurs, which were small, feathered dinosaurs that lived during the Late Jurassic period. 

The fossil record shows that birds descended from dinosaurs and share many skeletal features with them, such as a wishbone, air-filled bones, and large leg muscles. 

Furthermore, the discovery of numerous feathered dinosaur fossils, including Archaeopteryx and Anchiornis, lends credence to the link between birds and dinosaurs.