Genus: Acamptonectes FISCHER, MAISCH, NAISH, KOSMA, LISTON, JOGER, KRÜGER, PEREZ, TAINSH & APPLEBY, 2012
Etymology: Greek, akamptos, "rigid" and Greek, nektes, "swimmer"; which means rigid swimmer.

Species: densus FISCHER, MAISCH, NAISH, KOSMA, LISTON, JOGER, KRÜGER, PEREZ, TAINSH & APPLEBY, 2012
Etymology: Latin, densus, "compact, tightly packed"; refering to the robust and tightly fitting bones of the occiput and to the tightly interlocking cervical and dorsal centra.

Holotype: GLAHM 132588

Locality: Speeton and Filey Area, North Yorkshire County, England, Southern United Kingdom.

Horizon: D2D horizon, Speeton Clay Formation.

Biostratigraphy:

Age: Basal Hauterivian Stage, Upper Neocomian Subepoch, Middle Early Cretaceous Epoch, Early Early Cretaceous.

Material: Fragmentary skull roof, mandible, axial skeleton and scapular girdle.

Paratypes:

Locality: Cremlingen Area, Lower Saxony State, Germany.

Horizon:

Biostratigraphy: Simbiskites concinnus/staffi zone.

Age: Upper Hauterivian Stage, Upper Neocomian Subepoch, Middle Early Cretaceous Epoch, Early Early Cretaceous.

Material:

SNHM 1284-R: Fragmentary skull roof, complete mandible, partial axial skelton and partial scapular girdle.

NHMUK R11185: Partial rostrum and mandible, fragmentary ribs and a complete right humerus.