Biodiversity

Friday, May 12, 2006

BIRDS EVOLVE FROM DINOSAURS

BIRDS EVOLVE FROM DINOSAURS

In general dinosaurs were animals which lived on earth 160 millions back. Dinosaurs went through an extinction, which ended their existence on land. Modern birds are considered as direct descendants of theropod dinosaurs (3). Birds are bipedal (two feet moving) warm-blooded animals which have feathers, forelimbs modified as wings and hollow bones (1).

Most palaeontologists argue about where do birds evolve from some says birds evolve from Cryptovolans and some says from Saurichian dinosaurs. All the palaeontologists agree on one thing that birds evolve from dinosaurs but they do not agree on which type of a dinosaur (1). Some Palaeontologists discovered that modern birds evolve from Cryptovolans than Archaeopteryx. Ornithischian (bird-hipped) dinosaurs have the same hip structure as birds, but some paleontologists believe that birds originate from the saurichian (lizard-hipped) dinosaurs

Some Palaeontologists believe that birds are the descendants of theropod dinosaur (2). Descendants of a single common ancestor are related. Some palaeontologists believe that since modern birds are dinosaurs therefore dinosaurs have not become extinct. Modern birds are classified by most paleontologists as belonging to the subgroup Maniraptora, “which are coelurosaurs, which are theropods, which are saurischians, which are dinosaurs" (3). Paleontologists refer to birds as avian dinosaurs and to all other dinosaurs as non-avian dinosaurs. Dinosaurs are referred "to as a synonym for non-avian dinosaur, and bird as a synonym for avian dinosaur (meaning any animal that evolved from the common ancestor of Archaeopteryx and modern birds)" (3).

Birds are living dinosaurs because birds evolved from theropod dinosaurs which means when the dinosaurs died out birds continued with the legacy. Some of birds resemble dinosaurs like the ostrich; they have feathers but cannot fly the same as some dinosaurs. They are both warm blooded animals and they take care of their offsprings. Some paleontologists believe that birds are dinosaurs so dinosaurs did not die out because birds are carrying the dinosaurs’ legacy. Where do birds really evolve from does anyone know where they do or it is another argument from paleontologists? Are birds rely related to the dinosaurs?

Non-avian (dinosaurs) theropods shows a clear distinction between a bird and non-bird and the non-avian theropods were closely related to birds. In northeast China scientists discovered that the small theropod dinosaurs had feathers just like the modern birds (2). Since modern birds and dinosaurs have common ancestor then dinosaurs did not die out. Palaeontologists agree on one thing that modern birds are dinosaurs but they are not sure about the type of dinosaurs. Most of the dinosaurs could not fly just like some birds such as Ostrich.

Reference:

1. Wikipedia contributors. Birds [Internet]. Wikipedia, The Free Encyclopaedia; 2006 May 8, 20:26 UTC [cited 2006 May 10]. Available from: http://en.wikipedia.org/wiki/Birds
2. Wikipedia contributors. Theropoda [Internet]. Wikipedia, The Free Encyclopaedia; 2006 Apr 2, 04:52 UTC [cited 2006 May 10]. Available from: http://en.wikipedia.org/wiki/Theropoda
3. Wikipedia contributors. Dinosaurs [Internet]. Wikipedia, The Free Encyclopaedia; 2006 May 9, 17:38 UTC [cited 2006 May 10]. Available from: http://en.wikipedia.org/wiki/Dinosaurs#Evolution_of_dinosaurs

Lethabo Mosomane
CSIR
Pretoria
0001
Tel: 27 12 841 2133
Fax: 27 12 842 3676
Mail: lmosomane@csir.co.za
http://lmosomane.blogspot.com/

1 Comments:

  • The usual comments...

    Write your own essay, don't just stick a bunch of quotes together. Also, use non-Wiki references please.

    Nick

    By Blogger NcK, at May 18, 2006 9:19 AM  

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