THE DINOSAURS WERE WARM-BLOODED ANIMALS

Dinosaurs were the warm-blooded vertebrate animals living on land for over 160 million years and it also said that they first appeared about 230 million years ago and their hearts was resembled of crocodiles. These organisms have back bone skeleton and also have four legs. Dinosaurs were discovered in "the 19th century and species such as pelycosaur Dimetrodon, the pterosaurs were found on the land. Another example of dinosaurs that were found in the water is ichthyosaurs, plesiosaurs, and mosasaurs. These species suffered a catastrophic extinction which made them dominated on land" (1).


During 1970s scientists started looking" the evidence indicating that the dinosaurs may be warm blooded animals and the evidence shows that the dinosaur started to stand straight and walk like animals because their legs were like the animals" (1). They also have big ribs cages like a mammal’s heart and lungs. The other thing is that they also had "bones containing channels for quick blood circulation which was also found in warm blooded animals" (1).


The palaeontologist believed that some of the dinosaurs were warm-blooded animals but at the beginning were believed to be the cold-blooded animals because of they were closely related to the cold-blooded animals known such as reptiles. The warm-blooded do" not rely on the environment, chemical reaction help them to create heat inside their body" (1) and this means that they can regulate their body temperature rather than relying their on the environment, they can also hunt anytime any where.


Beverly Eschberg says that dinosaurs were believed to be related to the reptiles, but some of these species behave like the warm blooded animals. It said that the dinosaurs were active and moving at a high speed. Other scientist says that they fossils about "the warm blooded animals that suffered from the heat in warmer climate were recognised" (1). Beverly says that the evidence such as bones, growth rate, histology, predators to prey, high speed, and rate of evolution etc shows that the dinosaurs are warm blooded animals and all these evidence convinced her that the dinosaurs were the warm blooded animals.


The palaeontologist discovered the fossils of the dinosaur’s heart and they decided to name it Willo. Russell believed that this heart shows that this species was a warm blooded animal. Warm blooded animals can maintain "their body temperature at any environment and they can also control it by increasing their metabolic rate when the temperature decreases" (1). Ostrom and Baaker are the ones of the Palentologists determined that dinosaurs are the warm blooded animals because they believed that these species grow quickly and cold blooded animals grow slowly.


In 1992 the scientists by names of Shower and Barrick believed that "dinosaurs were warm blooded animals because of the temperature that they were maintaining at their body core" (1). They provide the evidence of bones, so the isotopes from the dinosaur’s bones indicated that the dinosaurs were warm blooded animals. This is also because "the bones are composed of minerals and calcium phosphate (CaPO4) so the oxygen in this process exist in the form of two isotopes,160 and 180 and this ratio can be measured and this means that the species is warm blooded animals" (1). The bones of dinosaurs are rich in halversia canals that transport nutrients from the blood to the cells that down new bones.


Pateontologists have different thoughts about the evidence of the dinosaurs. There are some scientists who believed that dinosaurs were warm blooded animals and others believed that these animals were cold blooded animals and both have the evidence to prove their believe. I concluded saying that the dinosaurs were warm blooded animals because they can maintain their body temperature at favourable and unfavourable environmental conditions.


Reference:

1. Barrick, R and Shower, W. 1994. Bones isotopes [Internet] 2006 May 17,15:04 UTC [cited 2006 May 16:29] Available from:
http://www.dinoruss.org/de_4/5c52015.htm
2. Chang, G. 1999. Dinosaurs were hybrid of cold-blooded, warm-blooded animals [internet] 2006 May 09, 11:30 UTC [cited 2006 May 10] Available from: http://www.exn.ca/Html/Templates/topicpage.cfm?ID=19990122-51&Topic=Dinosaur

3. George, J. 1997. The isotopes in their bones suggest that dinosaurs were warm blooded [internet] 2006 May 09, 14:30 UTC [cited 2006 May 10] Available from: http://www.txtwriter.com/onscience/Articles/dinoblood.html

4. Discovery Channel. 1997. Bird-like dinosaur found in Argentina[online]2006 May 09, 15:03 UTC [Cited 2006 May 10] Available from:
http://www.exn.ca/Html/Templates/topicpage.cfm?ID=19970521-02&Topic=Dinosaur

5. Krystek, L. 1996. Hot and cold running dinosaurs [Online]2006 May 17,15:04 UTC [cited 2006 May 17] Available from:
http://unmuseum.mus.pa.us/colddino.htm

6. Morell, V. 1987. Were Dinosaurs warm-blooded? Evidence supporting the claim that dinosaurs were warm blooded from strongest to weakest [internet] 2006 May 07, 11:30 UTC [cited 2006 May 10] Available from:
http://www.cheathouse.com/essay/essay_view.php?p_essay_id=12829

7. Wikipedia contributors. Dinosaurs [Internet] wikipedia, the free encyclopaedia, 2006 May 09, 18:48 UCT [Cited 15:00 May 10]. Available from:
http://en.wikipedia.org.wiki/Dinosaurs


Lizzy Maluleke
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