Data from: Out of the tropics: Macroevolutionary size trends in an old insect order are shaped by temperature and predators

Global body size distributions are shaped by selection pressures arising from biotic and abiotic factors such as temperature, predation and parasitism. Here, we investigated the ecological and evolutionary drivers of global latitudinal size gradients in an old insect order (Odonata; dragonflies and damselflies). Phylogenetic comparative analyses revealed that global size variation of extant taxa is negatively influenced by both regional avian diversity and temperature. Interestingly, fossil data show that the relationship between wing size and latitude has shifted: latitudinal size trends had initially negative slopes but became shallower or positive following the emergence of birds 150 MYA. These changing size-latitude trends over geological time were likely driven by bird predation and high dispersal ability of large dragonflies. Our results therefore suggest that latitudinal size gradients were shaped by temperature but also by predators driving the dispersal of large-sized clades out of the tropics and in to the temperate zone.