Archaeopteryx
| Archaeopteryx Temporal range:Late Jurassic(Tithonian),
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|---|---|
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| The BerlinArchaeopteryxspecimen (A. siemensii). | |
Scientific classification
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | Theropoda |
| Clade: | Paraves |
| Family: | †Archaeopterygidae |
| Genus: | †Archaeopteryx Meyer,1861 (conserved name) |
| Type species | |
| †Archaeopteryx lithographica Meyer, 1861 (conserved name)
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| Referred species | |
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| Synonyms[1] | |
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Genus synonymy
Species synonymy
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Archaeopteryxis one of the most importantfossilsever discovered. It is a flying dinosaur from theUpper Jurassic,about 150millionyears ago. It shows theevolutionarylinkbetween non-aviantheropoddinosaursandbirds,but it is not the ancestor of modern birds.[2]
The firstArchaeopteryxwas found in 1860 nearSolnhofeninBavaria,Germany.Today, tenskeletonsand onefeatherofArchaeopteryxhave been found.[3]
Archaeopteryxwas a small carnivorous dinosaur withfeathersand wings. It had amouthwithteeth,clawson thehandsand a longtail.Today, it is known thatdromaeosaurs,and possibly most other extinct theropods, looked like birds and that many had feathers. When they are born, today'sSouth Americanhoatzinhave claws on theirwingswhen they are young, just likeArchaeopteryx.
Analysis
[change|change source]Thomas Henry Huxley( "Darwin's bulldog" ), who was acomparative anatomist,made a study of this nearly 150 years ago. He comparedArchaeopteryxwith a smalltheropoddinosaur,Compsognathus.Both of the fossils came from the same place:SolnhofeninBavaria,Germany.Thestratacome from the end of theJurassicperiod, about 144millionyears ago. He showed that both were very similar except for the frontlimbsandfeathersofArchaeopteryx.[4]E.D. Copealso came to the same conclusion.[5]
Huxley's study showed the basic relationship between birds and reptiles. He united them under the title ofSauropsida.His papers onArchaeopteryxand the origin of birds have been of great interest ever since. Huxley concluded that birds evolved from smallcarnivorousdinosaurs.[6][7]
Status today
[change|change source]Archaeopteryxused to be considered the first bird. Nowadays, it is not the only fossil of a bird-like dinosaur. A similar species calledAnchiornis huxleilived from 160 to 155 million years ago.[8]It had feathers on both front and rear legs, and could probablyglide.It may or may not have had some ability to fly. This discovery means we cannot sayArchaeopteryxis 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 wastemperature regulation,and probably alsosignalling(seeEpidexipteryx).
Many scientists nowadays do not considerArchaeopteryxa true bird (=a member of the lineageAves). They only consider it a relative of birds. This classification does not reflect a different evolutionary hypothesis, it simply defines Aves (birds) less broadly.[9]
Directly ancestral or not?
[change|change source]It may be thatArchaeopteryxis not directly ancestral to modern birds, but it is still a finetransitional 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 thenArchaeopteryxwould not exist, whether it is directly ancestral or not ".[10]
Related pages
[change|change source]Further reading
[change|change source]- Chambers P. 2002.Bones of contention: the fossil that shook science.London: John Murray.ISBN0-7195-6059-4
- Shipman P. 1998.Taking wing: Archaeopteryx and the evolution of bird flight.London: Weidenfeld & Nicolson.ISBN0-297-84156-4
References
[change|change source]
- ↑"Troodontidae Gilmore, 1924".theropoddatabase.Archived fromthe originalon 3 April 2019.
- ↑Benton M.J. 2015.Vertebrate palaeontology.Wiley BlackwellISBN978-1-118-40684-7,p. 274.
- ↑Mayr, Geraldet al2007. The tenth skeletal specimen of Archaeopteryx.Zoological Journal of the Linnean Society.149(1), 97–116.[1]
- ↑Huxley T.H. 1868. On the animals which are most nearly intermediate between birds and reptiles. Annals and Magazine of Natural History. 4th series.2:66–75.
- ↑Cope E.D. 1867. An account of the extinct reptiles which approached the birds.Proceedings of the Academy of Natural Sciences of Philadelphia.19:234–235.
- ↑Paul G. 2002.Dinosaurs of the Air, the evolution and loss of flight in dinosaurs and birds.p171–224 Johns Hopkins, Baltimore.ISBN0-8018-6763-0
- ↑Foster, Michael and Lankester, E. Ray (eds )1898–1903.The scientific memoirs of Thomas Henry Huxley.4 vols and supplement, Macmillan, LondonISBN1432640119
- ↑Hu D.; et al. (2009), "A pre-Archaeopteryxtroodontid theropod from China with long feathers on the metatarsus ",Nature,461(7264): 640–643,Bibcode:2009Natur.461..640H,doi:10.1038/nature08322,PMID19794491,S2CID205218015
- ↑Gauthier, J. & de Queiroz, K. 2001. Feathered dinosaurs, flying dinosaurs, crown dinosaurs, and the name "Aves". pp. 7–41. In Gauthier, J. & Gall, L.F. (eds.)New Perspectives on the Origin and Early Evolution of Birds: Proceedings of the International Symposium in Honor of John H. Ostrom.New Haven: Peabody Museum of Natural History.ISBN0-912532-57-2hdl: 10088/4690
- ↑Theunissen, Lionel 1997. TalkOrigins Archive