Complex sentence: The holotype and only specimen of "Proplanicoxa", BMNH R 8649, identified from thirteen dorsals, a sacrum with ilia, parts of the pubis and ischium found in 1916 by Reginald Walter Hooley on the Isle of Wight from the upper Wessex Formation of England.
Split into simpler sentences: The holotype and only specimen of "Proplanicoxa", BMNH R 8649, is composed of thirteen dorsals, a sacrum with ilia, parts of the pubis and ischium. The fossils were found in 1916 by Reginald Walter Hooley on the Isle of Wight from the upper Wessex Formation of England.