Genus: Apatornis MARSH, 1873
Etymology: Greek, apatos, "deceive” and Greek, ornis, “bird”: in referring to the biconcave shape of its vertebrae, “deceptively” like those of a fish. “Deceptive Bird”.

Species: celer (MARSH, 1873) MARSH, 1873
Etymology: Latin, celer, "swift."
= Ichthyornis celer MARSH, 1873

Holotype: YPM 1451

Locality: Butte Creek, near Smoky Hill River, Logan County, Kansas.

Horizon: “yellow chalk of the Pteranodon beds”, Smoky Hill Member, Niobrara Formation.

Biostratigraphy:

Age: Coniacian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.

Material: Sacrum.

Referred material:

HOPE, 2002

Locality: Grove County, Kansas.

Horizon: Smoky Hill Member, Niobrara Formation.

Biostratigraphy:

Age: Coniacian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.

Material:

RTMP 88.222.5: Coracoid.