The earliest Pupipara (Diptera: Hippoboscoidea): A new genus and species from the lower Eocene of the Green River Formation

Eornithoica grimaldii gen. et sp. nov., the currently earliest Pupipara, is described from the lower Eocene of the Green River Formation. The previously oldest representative of this clade was from the Oligocene. The new fossil has some plesiomorphic character states, suggesting a 'basal' position in the clade. Its age, around 52 Ma, suggests that these epizooic ectoparasitic flies originated during the Paleocene or even the latest Cretaceous, prior to the first bats, if the latter. As is the case for several early diverging hippoboscids that feed on birds, E. grimaldii possibly victimized birds or terrestrial mammals. This study is a further example of the quantity of new information that can be obtained by the examination of fossil insects under UV light.

Automated summary

Eornithoica grimaldii gen. et sp. nov., the earliest known Pupipara, was discovered in the lower Eocene of the Green River Formation. This fossil, dating back to around 52 Ma, suggests that epizooic ectoparasitic flies may have originated during the Paleocene or late Cretaceous, preceding the first bats. E. grimaldii likely parasitized birds or terrestrial mammals, exhibiting plesiomorphic characteristics. This study highlights the significance of examining fossil insects under UV light for obtaining new information.