Dinosaur renaissance "reptiles" and birds. Shortly after the 1859 publication of Charles Darwin's "The Origin of Species", British biologist and evolution-defender Thomas Henry Huxley proposed that birds were descendants of dinosaurs. He cited skeletal similarities, particularly among dinosaurs, the "first bird"—"Archaeopteryx"—and modern birds. However, in 1926, Gerhard Heilmann wrote his influential book "The Origin of Birds", in which he dismissed the dinosaur–bird link, based on the dinosaurs' supposed lack of a furcula. Thereafter, the accepted hypothesis was that birds evolved from crocodylomorph and thecodont ancestors, rather than from dinosaurs. This removed dinosaurs from a central role in debates about the origin of
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