Archaeopteryx

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Archaeopteryx
Temporal range: Upper Jurassic
150.8 – 148.5 mya
Model at Geneva museum.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Family: Archaeopterygidae
Huxley, 1871
Genus: Archaeopteryx
Species: A. lithographica
The Berlin Archaeopteryx (original)
The London specimen (cast)

Archaeopteryx is one of the most important fossils ever discovered. It is a bird from the Upper Jurassic, about 150 million years ago. It shows the evolutionary link between reptiles and birds. The first Archaeopteryx was found in 1860 near Solnhofen in Bavaria, Germany. Today, nine skeletons and one feather of Archaeopteryx have been found.

Archaeopteryx looks like a reptile with wings and feathers. It had a mouth with teeth, claws at the hands and a long tail like dinosaurs or reptiles. Today, it is known that some dinosaurs looked like birds and that some had feathers. When they are born, today's South American hoatzin have claws on their wings when they are young, just like Archaeopteryx.

The analysis[change | change source]

Thomas Henry Huxley ("Darwin's bulldog"), who was a comparative anatomist, made a study of this nearly 150 years ago. He compared Archaeopteryx with a small theropod dinosaur, Compsognathus. These two fossils came from the same place: Solnhofen in Bavaria, Germany. The strata come from the end of the Jurassic period, about 144 million years ago. He showed that the two were very similar, except for the front limbs and feathers of Archaeopteryx.

Huxley's study showed the basic relationship between birds and reptiles. He united them under the title of Sauropsida. His papers on Archaeopteryx and the origin of birds were of great interest then and still are. Huxley concluded that birds evolved from small carnivorous dinosaurs.[1][2]

Status today[change | change source]

Only one dinobird has been found at a time before Archaeopteryx. It is called Anchiornis huxlei, from 160 to 155 million years ago.[3] It had feathers on both front and rear legs, and could certainly glide. It may or may not have had some ability to fly. This discovery means we cannot say Archaeopteryx is the first known bird, but its contribution to science has been huge. We now know for sure that a whole group of small theropod dinosaurs had feathers, and that flight was a later, secondary, use of feathers. The first use of feathers was temperature regulation.

Directly ancestral or not?[change | change source]

It may be that Archaeopteryx is not directly ancestral to all birds, but it is still a fine transitional fossil.

"Archaeopteryx, for example, is not necessarily directly ancestral to birds. It may have been a species on a side-branch. However, that in no way disqualifies it as a transitional form, or as evidence for evolution. Evolution predicts that such fossils will exist, and if there was no link between reptiles and birds then Archaeopteryx would not exist, whether it is directly ancestral or not".[4]

Related pages[change | change source]

Further reading[change | change source]

  • Chambers P. 2002. Bones of contention: the fossil that shook science. London: John Murray. ISBN 0-7195-6059-4
  • Shipman P. 1998. Taking wing: Archaeopteryx and the evolution of bird flight. London: Weidenfeld & Nicolson. ISBN 0-297-84156-4

References[change | change source]

  1. Paul G. 2002. Dinosaurs of the Air, the evolution and loss of flight in dinosaurs and birds. p171–224 John Hopkins, Baltimore. ISBN 0-8018-6763-0
  2. Foster, Michael and Lankester, E. Ray (eds )1898–1903. The scientific memoirs of Thomas Henry Huxley. 4 vols and supplement, Macmillan, London ISBN 1432640119
  3. Hu, D; Hou, L.; Zhang, L. & Xu, X. (2009), "A pre-Archaeopteryx troodontid theropod from China with long feathers on the metatarsus", Nature 461 (7264): 640–643, doi:10.1038/nature08322, PMID 19794491
  4. Theunissen, Lionel 1997. TalkOrigins Archive