Until the 1960s, dinosaurs were thought to be cold-blooded animals, which means they could not regulate their body temperature. Reference 1 describes how the ¹⁸O/¹⁶O ratio in dinosaur bones suggests that some species were warm blooded. Find reference 1, preferably at http://pubs.acs.org/ac if your institution has an electronic subscription to Analytical Chemistry. Explain how ¹⁸O/¹⁶O the ratio implies that an animal is warm or cold blooded. Explain the criteria that were used to determine the likelihood that ¹⁸O/¹⁶O in bone phosphate was altered after the dinosaur died. Describe how bone samples were prepared for analysis of oxygen isotopes and state the results of the measurements.