The type species Odontopteryx toliapica is known from the Ypresian (Early Eocene) London Clay of the Isle of Sheppey (England) and slightly older rocks of the Ouled Abdoun Basin (Morocco).

Though the Mexican specimen (MHN-UABCS Te5/6–517, a distal humerus piece) agrees with O. toliapica in size and shape, it is not entirely clear whether the American forms belong in this otherwise Eurasian genus.

[5] Pseudodontornis tschulensis[verification needed] from the Late Paleocene of Zhylga (Kazakhstan) is sometimes placed in Odontopteryx, as is Macrodontopteryx oweni which was also found in the London Clay.

[7] O. toliapica is among the smallest pseudotooth birds known to date – but this still means that to would have rivalled, if not exceeded, most living albatrosses in wingspan and the brown pelican (Pelecanus occidentalis) in bulk.

It resembles Dasornis in having a jugal arch that is mid-sized, tapering and stout behind the orbital process of the prefrontal bone, unlike in the large Neogene Osteodontornis.

Its quadrate bone, meanwhile, differed from that of Osteodontornis in a very broadly grooved dorsal head, a wide main shaft with a strongly curved lateral ridge and a small and somewhat forward-pointing orbital process.

[9] Odontopteryx differed from Pelagornis (a contemporary of Osteodontornis) and agreed with Dasornis[10] in having a deep and long handward-pointing pneumatic foramen in the fossa pneumotricipitalis of the humerus, a latissimus dorsi muscle attachment site on the humerus that consists of two distinct segments instead of a single long, and a large knob that extends along the ulna where the ligamentum collaterale ventrale attached.

Further differences between Odontopteryx and Pelagornis are found in the tarsometatarsus: in the present genus, it lacks a deep fossa of the hallux' first metatarsal bone and its middle toe trochlea is conspicuously expanded forward.