Archaeopteryx (if not colour banded) to some degree, so the darkness was attributed to such impurities. They also mention that a complete absence of air bubbles in the rock slabs is further proof that the specimen is authentic. Modern paleontology has often classified "Archaeopteryx" as the most primitive bird. It is not thought to be a true ancestor of modern birds, but rather, a close relative of that ancestor. Nonetheless, "Archaeopteryx" was often used as a model of the true ancestral bird. Several authors have done so. Lowe (1935) and Thulborn (1984) questioned whether "Archaeopteryx" truly was the first bird. They
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