Specimens of Archaeopteryx feather's earlier discovery, von Meyer made the London fossil the type specimen of the genus ("Archaeopteryx") and species ("lithographica"), establishing it as the exemplar of the species' features. Its discovery and subsequent descriptions, a mere handful of years after Darwin's "On the Origin of Species", fulfilled the hope of a truly transitional form in its then-unique amalgamation of bird and reptilian characters. The specimen is preserved on two counter slabs broken originally into four pieces. The main, overlaying slab contains most of the skeletal elements, while only impressions and a few bone fragments are visible on the counter slab. This
Specimens of Archaeopteryx on the main slab. Both arms are preserved close to their natural articulation with the shoulder girdle, though displaced. The ulna is more robust and curved than the slender radius. A confusing jumble of metacarpals has led some researchers to conclude the beginning of fusion between carpals and metacarpals; this has been rejected by later researchers. Most manual bones of the right wing are missing, and the left wing preserves two metacarpals, the semilunate carpal, and two long, slender phalanges with large, strongly-curved claws. The missing third finger led Owen to conclude a two-fingered hand for "Archaeopteryx" in his original