Australasian Science: Australia's authority on science since 1938

Delving into Dinosaur Body Temperatures

By John Long

New research finds that the dinosaur ancestors of birds had quite high body temperatures.

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In 2010 I was working in Los Angeles when I met a young PhD student from England working at Caltech named Rob Eagle. Working with Prof John Eiler, they set up a lab to try and solve one of the greatest mysteries of palaeontology: determining the body temperatures of dinosaurs.

Since the revelation that birds had evolved from feathered theropod dinosaurs, an hypothesis supported by the late 1990s discoveries of Chinese dinosaurs with feathered bodies and wing-like arms, the burning question had been about when birds first acquired their warm-blooded metabolism. Did the theropod dinosaurs have warm-blooded lifestyles well before they evolved into birds? The functional biomechanics of their skeletons indicated that they should have had a high metabolism and were likely to be warm-blooded, as birds and mammals are today.

To solve this problem, Eagle and Eiler developed an entirely new approach using clumped isotope thermometry, a technique to measure the temperature that calcitic bonds form in making organic frameworks inside bone or teeth. It works because rare isotopes of carbon-13 and oxygen-18 in apatite, the mineral that forms bone, bond with each other at certain temperatures. Measuring the degree of this “clumping” determines the exact temperature of the environment in which the bonds form inside bone or teeth –and thus the body temperature of the...

The full text of this article can be purchased from Informit.