Parahesperornis

Parahesperornis is a genus of prehistoric flightless birds from the Late Cretaceous. Its range in space and time may have been extensive, but its remains are rather few and far between, at least compared with its contemporary relatives in Hesperornis. Remains are known from central North America, namely the former shallows of the Western Interior Seaway in Kansas. Found only in the upper Niobrara Chalk, these are from around the Coniacian-Santonian boundary, 85–82 million years ago (mya). thumb|left|Photograph of scutes and feather impressions of the tarsal region of specimen (KUVP 2287) published by Williston (1898) in the University Geological Survey of Kansas Parahesperornis alexi (Martin, 1984) was long lumped with specimen YPM 1478, described initially as Hesperornis gracilis and later moved to the monotypic genus Hargeria (Lucas, 1903). It then turned out that this genus' description actually referred to specimen KUVP 2287, which eventually became the holotype of P. alexi. Nonetheless, the taxon description of Hargeria was about "Hesperornis" gracilis exclusively, and thus despite the misidentification it applies to YPM 1478, the holotype of "H." gracilis. This mistake was rectified by later authors, who sank Hargeria back into Hesperornis.

In 2017, Asiahesperornis was considered as a possible synonym of Parahesperornis.