Evolution is a very curious thing. Throughout history you can trace how different species, with no common ancestor, separated by millions of years, have come to develop similar features. A fact, which proves that if a certain quality gives you an advantage against your competitors, sooner or later it will prevail and become dominant. For example, flying has evolved on our planet on at least four distinct occasions. First were the insects, the most diverse group of animals on the planet, more than 350 million years ago. Second came the reptiles – the pterosaurs were the first vertebrates to take to the skies, before approximately 228 million years. They were closely related to the dinosaurs, although they were no dinosaurs themselves and to this day remain the largest flying creatures ever to have lived on Earth. After them, around 150 million years before our time, rose the birds and finally, the bats, the only flying mammals, developed roughly 60 million of years ago. There are actually over 1,200 different species of bats today, representing around 20% of all classified mammals. But such a complicated process did not develop overnight. It itself took millions of years and scientist are still not sure on the exact way that it happened. Some believe that it evolved from animals, living in the treetops, who first learned to glide down, until they finally took flight. Others believe that it was exactly the other way around with land-based animals beginning to make increasingly longer leaps. On thing is for sure, these changes took a lot of time and went through a variety of species, before they truly emerged. Such species are called transitional species.
When Charles Darwin published his famous book “The Origin of Species” in 1859, in which he put forth his theory of evolution, one of his biggest problems was that there was scarce proof in support of his ideas. In his work he actually predicted that fossils would be discovered, which would show the transitions from one species to another but was met with great skepticism. This however all changed just two years later with the discovery of the Archaeopteryx, which was soon dubbed the first bird. The fossil was unearthed near Solnhofen in Bavaria, Germany and showed a beautifully preserved specimen, which had both reptilian, as well as avian features. It had claws on the tips of its wings and large talons on its feet, similar to a raptor. Unlike modern birds it also had a full set of teeth and a long bony tail. However, it had feathers, its bones were hollow, and its collarbones had fused together – an important step in enabling the wings to flap efficiently. The structure and arrangement of the feathers suggested it was able to fly, although if it was capable of powered flight like modern birds or was more of a glider is still a subject of debate. Its feet were also covered in feathers, a characteristic not featured in among birds today. That’s why some scientists believe that feathers originally developed as a type of improved insolation, to better regulate body head and at first were unrelated to flying.
As of yet a total of 12 fossils have been discovered, all in the same limestone rocks in Germany, although one of them has since been classified to a different species, making them extremely rare. The most complete fossil is known as the Berlin specimen and was found sometime between 1874 and 1875. It was reportedly discovered by a farmer, who sold it off to raise the money to buy a cow. It was then placed on sale at auctions and eventually sold to the Berlin Natural History Museum. The deal was financed by Ernst Werner von Siemens, the founder of Siemens and for that the particular species bears his name - A. siemensii.
The Archaeopteryx’s reputation as the first bird ever does seem to be a bit overblown. Discoveries of similar species at the end of the 20th and during the 21th century in China, Mongolia and Argentina suggest that it was indeed not a predecessor, but a close cousin to the birds’ ancestors. Some scientists believe it should be reclassified to the dinosaur group Deinonychosauria, a group which also contains the Velociraptors and Microraptors. Furthermore, another species from China with very similar features, Xiaotingia zhengi, does appear to be around 5 million years older than the Archaeopteryx.