On Insectivorous Pterosaurs and Mammals
It has often been suggested that modern terrestrial insectivorous mammals like shrews are nocturnal due to competition with diurnal insectivorous birds, which also forage on the ground, and overall occupy a nigh identical ecological niche, as anyone familiar with robins can attest.
Many insectivorous pterosaurs might have actually foraged on the ground; only anurognathids and the smaller “campylognathoidids” show significant adaptations for hawking.
What if in the Mesozoic insectivorous pterosaurs similarly “opressed” mammals, forcing them into nocturnal niches? Better yet, what if it was competition from pterosaurs that drove small mammals into nocturnal niches, with the current state being an ecological ghost mildly supported from competition with birds?