Figure 3. Temperature differences between skeletal elements and temperature variabilities within individual bones are plotted. Mean interbone temperature differences are shown in blue. Temperatures represent degrees colder than the bone with the most negative mean isotopic value (caudal #4). Vertebrae are all within 0.6°C of each other. Intrabone temperature variability is represented in brown/tan. Bars represent the range of temperature variation within the skeletal element. Homeothermic endotherms will have less than 4°C core temperature variability and (depending upon climate) increasing variability in the limbs and shell body. The core body (represented by the cervical and dorsal centra show 2-3°C temperature variability, while the ribs, limbs and tail vertebrae show temperature variabilities of 2.5-5.8°C. Skeletal elements on the vertical axis are arranged from anterior (bottom) to posterior (top), vertebrae (blue), ribs (green), pubis (black), and limbs (red).