14 DAY TRIAL // In a new scientific study, it was revealed that analyzing the isotopic signature of various chemicals found in the bone, and especially the teeth, of ancient animals could give researchers more clues as to how warm the creatures' bodies were. The new investigations method relies on looking at the way in which very rare isotopes of carbon and oxygen clump together in these samples. With the technique, it may finally be possible to put an end to the never-ending debate that has been raging on inside the international scientific community, about the temperatures at which the bodies of dinosaurs functioned best, Nature News reports.
According to the research team that developed the new method, the approach could also be used to derive additional data on the temperature of the world's oceans at various moments in our planet's history. The conclusions of the study appear in a paper published in the latest issue of the esteemed journal Proceedings of the National Academy of Sciences (PNAS). The tow main isotopes on which the technique relies are carbon-13 (13C) and oxygen-18 (18O). They cluster together in a very peculiar manner inside bioapatite, which is a mineral that develops in bone, teeth and scales. The accumulation process is very prone to external influences, including that of temperature.
The mineralization event is hindered by heat, which tends to scatter the atoms, and therefore change the basic composition of the mineral itself. “At 5 degrees Celsius, you'll get much more 13C–18O bonding than you would at 100 degrees Celsius,” explains Robert Eagle, who was the lead author of the new PNAS paper. He holds an appointment as a geochemist at the Pasadena-based California Institute of Technology (Caltech), in the Division of Geological and Planetary Sciences. He says that the new method can be used on biological samples, if a few simple steps are followed.
He exemplifies by saying that bone, shell and tooth fragments are dissolved in acid. Only a minute section is needed, so no one would ever have to destroy a sample in order to analyze it. The carbon dioxide gas that forms after the acid does its part of the job is then ran through a high-sensitivity mass spectrometer. This machine is capable of detecting the faint light signature of virtually any chemical known, and is therefore able to produce a dataset showing what chemicals exist in a sample, and in what proportion. The researchers can then use this data to establish the age of their samples.