The oldest feather in the world belonged to the dinosaur Anchiornis huxleyi, which was found in China and dates back 150 to 160 million years.
Scientists believe that lightweight dinosaurs like Compsognathus evolved to run on two legs.
Archeopteryx is the oldest known bird, living between 155 and 150 million years ago. They had feathers similar to modern birds but teeth like reptiles.
Although Archeopteryx could fly, they were unable to take off directly from the ground. They likely climbed trees before launching themselves into the air.
Archeopteryx was crow-like in shape, with a wingspan of 60 cm, and is recognized as having the oldest known wings.
Titanis walleri lived in North and South America between two and five million years ago. They had beaks up to 50 cm long and tails up to 2.5 meters in length. However, they could not use their small wings for flight.
Ichthyornis was a seabird with long, toothed jaws that lived during the Cretaceous period alongside dinosaurs.
Ichthyornis is the earliest known bird to have a slender, high pectoral bone attached to the chest muscles, which increased their wing strength.
Diatryma was a large, flightless seabird from 70 million years ago. It hunted fish by diving underwater using its strong swimming abilities.
The ancient, flightless Diatryma lived in North America and Europe about 50 million years ago. They stood on two-meter-long legs and likely used their powerful, hook-like beaks to hunt mammals.
Birds of prey, widely known as terror birds, include Titanis walleri. This species likely went extinct 10 to 20 million years ago. These flightless birds could chase prey at speeds of 64 km/h and used their beaks like axes to kill their prey.
Argentavis was a native North American member of the vulture family, boasting an astonishing 7.3-meter wingspan.
