[2] The holotype specimen (MNHNL BU159) was discovered during a temporary excavation for a roadway upgrade between the Montois-la-Montagne and Sainte-Marie-aux-Chênes communes in Lorraine, France.

The remains consisted of a near-complete mandible, coracoid shoulder bone, a tooth, and fragments of the upper jaw and front limb.

They specifically originated from a section of the Marnes de Gravelotte, a marl deposit dated to the Bajocian stage of the Middle Jurassic around 168 mya.

[2] The generic identification was doubted by the PhD thesis of Noè (2001),[3] but it was not until at least 2021 that the holotype began to be rigorously reexamined by Sven Sachs of the Bielefeld Natural History Museum.

This thus warranted a new genus, which they named Lorrainosaurus, a portmanteau of the type locality Lorraine and Ancient Greek σαῦρος (sauros, "reptile").