P3R1O1B3O1S1C3I1D2E1A1N1S1
20 points
PROBOSCIDEANS is validvalid
PROBOSCIDEAN,
PROBOSCIDEAN, any of an order of large mammals comprising the elephants and extinct related forms, also PROBOSCIDIAN
PROBOSCIDEAN,
PROBOSCIDEAN, any of an order of large mammals comprising the elephants and extinct related forms, also PROBOSCIDIAN