5
edits
Changes
→Evolutionary view
{{QuoteBox|Several features, including a carinate sternum and reduced fibula, suggest that ''Mononychus olecranus'' is more closely related to modern birds than is ''Archaeopteryx lithographica''. The two skeletons are among the best preserved fossils known of a primitive bird, and emphasize the complexity of the morphological transformation from nonavialian theropods to modern birds. The occurrence of such a primitive bird in the Late Cretaceous reflects the paucity of Mesozoic bird fossils and suggests that the early radiation of avialians is only beginning to be sampled
{{QuoteBox|Several features, including a carinate sternum and reduced fibula, suggest that ''Mononychus olecranus'' is more closely related to modern birds than is ''Archaeopteryx lithographica''. The two skeletons are among the best preserved fossils known of a primitive bird, and emphasize the complexity of the morphological transformation from nonavialian theropods to modern birds. The occurrence of such a primitive bird in the Late Cretaceous reflects the paucity of Mesozoic bird fossils and suggests that the early radiation of avialians is only beginning to be sampled
<ref>''Nature'' 362, 623-626 ([[15 April]] [[1993]])</ref>}}
<ref>''Nature'' 362, 623-626 ([[15 April]] [[1993]])</ref>}}
=Evolution of flight=
'''Cursorial Theory'''
Proposed in 1879 by fossil expert [[Samuel Williston]], the Cursorial Theory suggests that the ancestors of birds were ground dwelling theropods that developed flight through leaping and jumping. Cursorial Theory is no longer popular among scientists, who generally favor the Arboreal "trees down" theory of flight, since taking off from the ground is energetically expensive, thus it is not likely that flapping flight evolved from the ground up. However, proponents of Cursorial theory point to the basilisk lizard, which possesses the ability to run on water for a short time to escape predators, yet also the ability to climb with great agility. The ability to run bipedally is not evident when the basilisks anatomy alone is taken into account, indeed what the basilisk illustrates best is the plasticity of animal behavior. It is nearly impossible to pin down an animals behavior simply by looking at its anatomy, animals are capable of twice the behavior their anatomy would suggest, sometimes more. Vertebrates consistently illustrate throughout their history that adaptive behavior probably evolves before anatomy in adapting to new niches and habitats.
==References==
==References==