Genus: Eoplesiosaurus BENSON, EVANS & DRUCKENMILLER, 2012
Etymology: Greek, eo, "dawn" + Plesiosaurus, referring to a proportionally long neck, which is also present in Plesiosaurus.

Species: antiquior BENSON, EVANS & DRUCKENMILLER, 2012
Etymology: Latin, antiqua, "ancient" meaning 'more ancient', in reference to the old geologic age of the specimen and Dura antiquior (''a more ancient Dorset'; 1830), a watercolour depection of Lower Jurassic fauna, including plesiosaurs and ichthyosaurs, by Henry de la Beche.

Holotype: UK [TTNCM] 8348

Locality: Watchet, Somerset, Somersetshire County, England, Southern United Kingdom.

Horizon:

Biostratigraphy:

Age: Lowermost Hettangian Stage, Lowermost Lias Epoch, Earliest Jurassic.

Material: A postcranial skeleton.