The holotype specimen of Dolichorhynchops osborni, KUVP 1300, was discovered in the upper Smoky Hill Chalk Logan County, Kansas, by George Fryer Sternberg, as a teenager, in around 1900.

[3] The specimen was eventually mounted in plaster and was acquired by the Harvard Museum of Comparative Zoology.

(See also Everhart 2004b) The specimen of D. osborni on exhibit at the Sternberg, FHSM VP-404[5] was found by Marion Bonner near Russell Springs in Logan County in the early 1950s.

The fossil was found close to the town of Herschel in southwestern Saskatchewan, from which the species name is derived.

The rock formation it was found in consists of sandstones, mudstones and shales laid down in the Western Interior Seaway, just before it began to revert to dry land.

[7] The type specimen of D. herschelensis was discovered in a disarticulated state (i.e. the bones were scattered about the discovery site).

The skull, lower jaw, ribs, pelvis and shoulder blades were all recovered, but the spine was incomplete, so the exact number of vertebrae the living animal would have had is unknown.

Assuming that only a few vertebrae are missing from the skeleton, the animal is estimated to be about 2.5–3 metres (8.2–9.8 ft) in length.

[7] Two very large specimens of a polycotylid plesiosaur (KUVP 40001 and 40002[8]) were collected from the Pierre Shale of Wyoming and later reported on by Adams in her 1977 Masters thesis.