The convex-billed cowbird (Pandanaris convexa) is an extinct species of bird in the family Icteridae, described in 1947 by Alden H. Miller.

[1] Pandanaris convexa has an upper mandible (7.0 mm in length) similar to that of the extant cowbirds in the genus Molothrus, though its narial opening is approximately 30% larger.

[2][3][4] Along with many other birds of the late Quaternary, the convex-billed cowbird likely co-evolved with Pleistocene megafauna, inhabiting the grassland habitats that were shaped by these species and feeding on the insects that their foraging stirred up.

The other still-extant icterid species that also inhabited the same areas, such as the red-winged blackbirds and orchard orioles, may have also been extirpated from these altered habitats, but the species as a whole were able to tolerate them, with some populations surviving in other areas and later recolonizing the altered habitats they were previously extirpated from.

In contrast, Pandanaris may have been so wholly dependent on megafaunal communities that it could not tolerate the altered habitats and went fully went extinct throughout its range.