Evolution of birds extinction event 66 million years ago, giving rise to ostriches and relatives (Paleognathae), ducks and relatives (Anseriformes), ground-living fowl (Galliformes), and “modern birds” (Neoaves). Phylogenetically, Aves is usually defined as all descendants of the most recent common ancestor of a specific modern bird species (such as the house sparrow, "Passer domesticus"), and either "Archaeopteryx", or some prehistoric species closer to Neornithes (to avoid the problems caused by the unclear relationships of "Archaeopteryx" to other theropods). If the latter classification is used then the larger group is termed Avialae. Currently, the relationship between dinosaurs, "Archaeopteryx", and modern birds is still under
Archaeopteryx seizing it with its jaws if it was small enough, or with its claws if it was larger. Over the years, twelve body fossil specimens of "Archaeopteryx" and a feather that may belong to it have been found. All of the fossils come from the limestone deposits, quarried for centuries, near Solnhofen, Germany. The initial discovery, a single feather, was unearthed in 1860 or 1861 and described in 1861 by Hermann von Meyer. It is currently located at the Natural History Museum of Berlin. This is generally assigned to "Archaeopteryx" and was the initial holotype, but whether it is a