Study shows a few dinosaurs may have been warm blooded

For more than 150 years, scientists have been debating on the body temperatures of dinosaurs and whether the body temperatures had an impact on their activity levels.

The new findings indicate that at least half of all dinosaurs possessed the ability to increase their body temperature through heat sources in the environment. “They may have been intermediate-somewhere between modern alligators and crocodiles and modern birds; certainly that’s the implication for the oviraptorid theropods”.

The study was published today, October 13, in the journal Nature Communications.

“This technique tells you about the internal body temperature of the female dinosaur when she was ovulating”, said co-author Aradhna Tripoli, a UCLA assistant professor of geology, geochemistry and geobiology. In the case of an egg, scientists can use this ratio to estimate the temperature of the mother’s body when she formed it.

The egg shells that came from Argentina are about 80 million years old and belong to large long-necked titanosaur sauropods, which belong to a family including the largest animals that have roamed the Earth.

Oviraptors are fairly closely related to the first birds that evolved so being warm-blooded probably emerged in dinosaurs and was passed onto birds. Smaller, two-legged omnivorous oviraptors were estimated to have had a body temperature of 89.4 degrees Fahrenheit.

Now, an worldwide team of researchers is uncovering new clues about dinosaurs’ body temperatures.

Warm-blooded animals typically need to eat a great deal to stay warm, forcing them into frequent hunts or to eat large quantities of plants. There may even be several other dinosaurs that were warm-blooded and that there is probably a spectrum and not a distinct difference between being an endotherm and an ectotherm.

Chilly-blooded animals, or ectotherms, together with alligators, crocodiles and lizards, depend on exterior environmental warmth sources to control their physique temperature. Lizards, for example, often sit on rocks in the sun to absorb heat, which allows them to be active. “If dinosaurs were endothermic to a degree, they had more capacity to run around searching for food than alligators would”.

The researchers also analyzed fossil soils, including minerals that formed in the upper layer of the soil on which the oviraptorid theropods’ nests were built.

In the big question therefore of warm- versus cold-blooded, when it comes to dinosaurs, the study suggests the answer is somewhere in between.

Eagle, who is also LabEx worldwide Chair of the European Institute of Marine Sciences, and his colleagues measured the bonds between two heavy isotopes, Carbon-13 and Oxygen-18, in the calcium carbonate mineral that makes up the hard part of eggshells. Mineral forming inside colder our bodies has extra clustering of isotopes. In addition they analyzed fossilized dinosaur eggshells from France, however discovered these weren’t nicely-preserved, and excluded them.

Scientists from the University of California, Los Angeles (UCLA) have been studying fossilized dinosaur eggshells found in Argentina and Mongolia. NSF funds reach all 50 states through grants to almost 2,000 colleges, universities and other institutions.