Many fossils of early birds and small dinosaurs have been discovered in the Liaoning Province of Northeast China. These include "Anchiornis huxlei", from about 160 mya. The fossils show that most small theropod dinosaurs had feathers. These deposits have preserved them so well that the impressions of their feathers can be clearly seen. This leads us to think that feathers evolved first as heat insulation and only later for flight. The origin of birds lies in these small feathered dinosaurs.