Data from: Large-scale evolution of body temperatures in land vertebrates

Body temperature is a crucial variable in animals that affects nearly
every aspect of their lives. Here we analyze for the first time
large-scale patterns in the evolution of body temperatures across
terrestrial vertebrates (tetrapods, including amphibians, mammals, birds
and other reptiles). Despite the traditional view that endotherms (birds
and mammals) have higher body temperatures than ectotherms, we find they
are not significantly different. However, rates of body-temperature
evolution are significantly different, with lower rates in endotherms than
ectotherms, and the highest rates in amphibians. We find that body
temperatures show strong phylogenetic signal over 350 million years of
evolutionary history in tetrapods, and some lineages appear to have
retained similar body temperatures over time for hundreds of millions of
years. Although body temperatures are often unrelated to climate in
tetrapods, we find that body temperatures are significantly related to
day-night activity patterns. Specifically, body temperatures are generally
higher in diurnal species than nocturnal species, both across ectotherms
and, surprisingly, across endotherms also. Overall, our results suggest
that body temperatures are significantly linked to phylogeny and
diel-activity patterns within and among tetrapod groups, rather than just
climate and the endotherm-ectotherm divide.