Difference between revisions of "Archaeopteryx"

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(→‎Evidence for evolution?: Deleted questionable paragraph; see talk.)
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Furthermore, like other birds, both its maxilla (upper jaw) and mandible (lower jaw) moved.
 
Furthermore, like other birds, both its maxilla (upper jaw) and mandible (lower jaw) moved.
 
In most vertebrates, including many reptiles, only the mandible moves.<ref name="cw94" />
 
In most vertebrates, including many reptiles, only the mandible moves.<ref name="cw94" />
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More recently, CT scans of an ''Archaeopteryx'' braincase were compared to the brains of modern and more advanced fossil birds.  It was demonstrated that the brain of ''Archaeopteryx'' is not like modern birds.  Instead, the authors concluded that like its ankle, feet, and skull, the brain or ''Archaeopteryx'' is more like predatory dinosaurs than modern birds. <ref>Kurochkin, et al. "A fossil brain from the Cretaceous of European Russia and avian sensory evolution," The Royal Society Biology Letters, http://www.journals.royalsoc.ac.uk/(ovrnzmfyck1pbxfhjrjtxxeo)/app/home/contribution.asp?referrer=parent&backto=issue,3,33;journal,1,11;linkingpublicationresults,1:110824,1 </ref>
 
  
 
== External Links ==
 
== External Links ==

Revision as of 09:48, July 11, 2007

File:Archaeopteryx.png
Bird, or dinosaur?

Archaeopteryx is an extinct bird, known only from the fossil record. Ten specimens, including several complete, articulated specimens, have been found.

Evidence for evolution?

Archaeopteryx is often presented as evidence of evolution because the bones have some characteristics reminiscent of reptiles including teeth and incomplete evolution of the wing structure[Citation Needed], making it appear to be a transitional form between reptiles and birds.

The criticism of the Archaeopteryx as a transitional form has been strengthened by the work of creationary anatomist Dr. David Menton[1] suggesting that Archaeopteryx was a true bird with flight feathers, not a transitional form at all.

In 1993, an article was published in Science magazine arguing that the Archaeopteryx had fully-formed flying feathers (including asymmetric vanes and ventral, reinforcing furrows as in modern flying birds), the classical elliptical wings of modem woodland birds, and a large wishbone for attachment of muscles responsible for the downstroke of the wings[1]

While most evolutionary scientists agree that the flight feathers of Archaeopteryx were essentially modern, several papers since have argued against Feduccia's claims about the anatomy of Archaeopteryx[2] Specimens such as the Thermoplis Specimen [3] are thought to clearly show that the arms, wishbone, tail, feet, hips, and palate of Archaeopteryx were more like meat-eating theropod dinosaurs than modern birds.

The brain of Archaeopteryx was essentially that of a flying bird, with a large cerebellum and visual cortex.[4] Creationists argue that the fact that it had teeth is irrelevant to its alleged transitional status, as a number of extinct birds had teeth, while many reptiles do not.[4] Furthermore, like other birds, both its maxilla (upper jaw) and mandible (lower jaw) moved. In most vertebrates, including many reptiles, only the mandible moves.[4]

External Links

Sources

References

  1. ↑ A. Feduccia, "Evidence from Claw Geometry Indicating Arboreal Habits of Archaeopteryx," Science, 259(5096):790-793, February 5, 1993.
  2. ↑ "The tenth skeletal specimen of Archaeopteryx," Zoological Journal of the Linnean Society, 149:97-116, 2007.
  3. ↑ www.wyodino.org
  4. ↑ 4.0 4.1 4.2 Wieland, 1994