The old question about dinosaurs body temperature and if they had warm or cold blood may come to its end, since new information indicates that this answer could be an affirmative one. A few decades ago, paleontologists believed that all dinosaurs were animals similar to lizards and had a slower metabolism to coordinate their entire organism full of cold blood. These types of creatures, scientifically named ectotherms, must get most of their body warmth from the surrounding environment. On the opposite side, endotherms, including humans and the majority of mammals, are able to produce most of the warmth they need at an internal level.
Now, experts know that a large part of dinosaurs that lived tens of millions ago were actually birds’ predecessors. Modern birds are endothermic creatures, and have a very fast metabolism. Did dinosaurs possess a bird-like organism and the warm blood to survive in cold environments? An analysis released this week in US scientific journals seems to have discovered the answer in dinosaur eggshells.
The primary results are in accordance with what many studies have concluded over years: Prehistoric metabolisms were spread on a wide range of biological variety. Paleontologists says that it is important to understand that in ancient times there was actually a huge diversity among dinosaurs, even compared to contemporary animal kingdom.
Birds have various metabolic rates that are extremely high in comparison to those of humans, making them probably warmer than we are. Then, there are unusual creatures such as sloths, which are at the slowest and coolest side of animal blood temperature. The real dilemma is where dinosaurs were on this variety of biological diversity.
That is where experts’ studies come in to clarify this problem, at least a little. They examined the chemical composition of prehistoric eggshells, applying a method previously mastered on teeth to calculate the heat range of the body in which they have developed in. By estimating the variety of substance ties between a pair of rare and heavy isotopes (oxygen-18 and carbon-13) in carbonated minerals, researchers can calculate the organisms’ heat range.
An element that forms at lower temperatures can have a higher number of such ties than an identical element created at higher temperatures. Applied to eggshells, researchers can use these rates to calculate the heat range of their pregnant mother’s body during the development.
After proving that this technique worked in eggshells from today’s animals, the paleontologists tested a number of fossilized eggs. A significant part of these ancient eggs showed signs of corrosion that could alter any results about their temperature, but scientists were able to successfully evaluate two varieties of dinosaurs and found clues from diverse metabolic rates.
The first species was the long-necked sauropod titanosaur, and it has shown a pregnant body temperature of around 100 degrees F, comparable to that of large animals living today. The other species, an oviraptorid related to T-rex, indicated a much cooler body temperature of only 90 degrees Fahrenheit, which is considerably lower than that of most animals.
But possibilities are that both of these species were endothermic at some degree, as experts affirmed. Research of the ground near the oviraptorid eggs shows that the air might have been cooler than the dinosaurs’ temperature.
Image source: Wikipedia