Who: Pumiliornis tessellatus
Lagerstätte: Messel Pit in Germany
What: Pumiliornis is the oldest known flower-visiting bird in the fossil record at 47 million years old (Eocene Epoch). This is based on preserved pollen grains in its stomach! This strongly supports nectar-eating behavior further compounded by its beak which was long and likely flexible similar to hummingbirds. Fish and seeds have been found in birds stomach before, like the Jehol Biota in China, but pollen-finds are rarer and usually nectar-visiting behavior has to be inferred based on the fossil’s anatomy which can be difficult. Pumiliornis is not closely related to any known modern pollinators.
Mayr, Gerald, and Volker Wilde. “Eocene fossil is earliest evidence of flower-visiting by birds.” Biology Letters 10.5 (2014): 20140223.
O’Connor, Jingmai K., and Zhonghe Zhou. “The evolution of the modern avian digestive system: insights from paravian fossils from the Yanliao and Jehol biotas.” Palaeontology 63.1 (2020): 13-27.