Stories tagged fjgfcgjkhg

Aug
09
2006

Comparison of body temperatures: A plot of the relationship between average body temperature (°C) and the logarithm of body mass for dinosaurs and modern crocodiles.  This graph potentially shows the accuracy of the formula by applying it to modern crocodiles. Chart  courtesy Gillooly JF Allen AP, Charnov EL (2006) Dinosaur Fossils Predict Body Temperatures. PLoS Biol 4(8): e248.
Comparison of body temperatures: A plot of the relationship between average body temperature (°C) and the logarithm of body mass for dinosaurs and modern crocodiles. This graph potentially shows the accuracy of the formula by applying it to modern crocodiles. Chart courtesy Gillooly JF Allen AP, Charnov EL (2006) Dinosaur Fossils Predict Body Temperatures. PLoS Biol 4(8): e248.
The question regarding whether dinosaurs were warm-blooded or cold-blooded has been debated for decades. Currently, most scientists believe that dinosaurs were warm-blooded and used internal mechanisms to maintain a constant body temperature. However, what that internal body temperature was could have fluctuated depending on the size of the dinosaur, making it possible for dinosaurs to have been both.
The bigger the hotter
Researchers at the University of Florida devised a mathematical formula that describes the connection between temperature, growth rate and biomass across a wide range of modern creatures. They then applied this formula to newly available fossil data on the growth rates of eight dinosaur species.
The equation showed that the bigger a dinosaur was the hotter is was. Smaller dinosaurs had internal body temperatures of around 77º Fahrenheit, which was close to the average air temperature of their time, so could have regulated their body temperatures much like modern cold-blooded reptiles. As dinosaurs grew larger, and the ratio of their surface area to volume fell, they became less efficient as dissipating their own metabolic heat. Because of this increased internal body temperature, dinosaurs probably had to develop behavioral or other adaptations to avoid overheating.
Body temperature influenced dinosaur size
One of the larger dinosaurs studied, Sauroposeidon proteles, weighed nearly 120,000 pounds. Applying the mathematical formula reveals that it may have had a body temperature close to 118º Fahrenheit, which is about as hot as most living creatures can get before the proteins in their bodies begin to break down. Because of this, the size of the largest dinosaurs may have been limited by their internal body temperatures.