Genus: Proplanicoxa CARPENTER & ISHIDA, 2010
Etymology: Greek, pro-, "before" + Planicoxa; in reference to the ilum trending towards the horizontal postacetabular process seen in Planicoxa.

Species: galtoni CARPENTER & ISHIDA, 2010
Etymology: In honor of Peter Galton for his work on European ornithischians.

Holotype: NHMUK (old BMNH) R 8649

Locality: Southwest coast of Isle of Wight County, England, Southern United Kingdom.

Horizon: Upper half of the Wessex Formation.

Biostratigraphy:

Age: Late Barremian Stage, Lower Gallic Subepoch, Middle Early Cretaceous Epoch, Early Cretaceous.

Material: 13 dorsals, sacrum with ilia, parts of pubis and ischium.