Holding the No.8 spot in our countdown is an ancient creature named Archaeopteryx, whose discovery in the mid-1800s turned the world of paleontology upside down. It looked like some sort of feathered dinosaur, but it also had a number of bird characteristics. Was it a bird, a dinosaur or some other beast entirely? Clues would come in time, but only after decades of contentious debate and close examination.
In order to fully understand the natural history of Archaeopteryx, one needs first to take a look at some of its unusual characteristics. Its dinosaur features include a full set of teeth, a flat breastbone, a bone tail and claws on the end of its wing. On the other hand, its feathers and wings also made it quite birdlike. However, details of Archaeopteryx anatomy indicated that it was not ideally built for flight and probably spent as much time running, leaping, climbing and gliding as it did flying.
So what was this enigmatic animal? It is now widely believed that Archaeopteryx is the most primitive known bird, with several specimens dating back about 150 million years to the Jurassic Period. It is also an evolutionary link between modern birds and a group of dinosaurs that roamed the earth 150 million years ago. Thus, it is one of the most important fossil species ever found.