Genus: Xenoposeidon TAYLOR & NAISH, 2007
Etymology: Greek, xenos, "strange or alien," and Poseidon, the god of earthquakes and the sea in Greek mythology; the latter in reference to the sauropod SauroposeidonWedel, Cifelli, and Sanders, 2000

Species: proneneukos TAYLOR & NAISH, 2007
Etymology: Latin, pronus, "forward sloping"; describing the characteristic morphology of the neural arch.
= Neosauropoda Nova TAYLOR & NAISH, 2006

Holotype: BMNH R2095

Locality: Ecclesbourne Glen, East Sussex County, England, Southern United Kingdom.

Horizon: Hastings Beds.

Biostratigraphy:

Age: Berriasian-Valanginian Stage, Lower-Middle Neocomian Subepoch, Lower Early Cretaceous Epoch, Early Cretaceous.

Material: Partial mid-to-posterior dorsal vertebra.