Berlin specimen

Archaeopteryx fossils from the quarries of Solnhofen limestone represent the most famous and well-known fossils from this area. They are highly significant to paleontology and avian evolution in that they document the fossil record's oldest-known birds.

Over the years, eleven body fossil specimens of Archaeopteryx and a feather that may belong to it have been found. All of the fossils come from the upper Jurassic lithographic 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 Christian Erich Hermann von Meyer. The fossil consists of two counterslabs, designated BSP 1869 VIII 1 (main slab) and MB.Av.100 (counterslab). Its two counterslabs are currently located at the Bavarian State Collection of Paleontology and Geology of Munich University and the Museum für Naturkunde in Berlin, respectively. This feather is generally assigned to Archaeopteryx and was the initial holotype, but whether it actually is a feather of this species or another, as yet undiscovered, avialan is unknown. There are some indications it is indeed not from the same animal as most of the skeletons (the "typical" A. lithographica).

The feather was first described in a series of correspondence letters between Hermann von Meyer and Heinrich Georg Bronn, the editor of the German Jahrbuch für Mineralogie journal. Examining the fossil on both counterpart split slabs, von Meyer immediately recognized it as an asymmetrical bird feather, most likely from a wing, with an "obtusely angled tip" and a "here and there gaping vane", and noted its blackish appearance. Six weeks after writing this first letter in August 1861, von Meyer wrote again to the editor stating that he had been informed of a nearly-complete skeleton of a feathered animal from the same lithographic shale deposits, which would later be known as the London specimen. Coincidentally, von Meyer proposed the name Archaeopteryx lithographica for the feather, but not for the skeleton. Therefore, the official name of the animal was originally linked to the single feather rather than any actual skeleton, and is formally considered the original holotype.

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Wikipedia