A Scutum was a shield.
Soldiers fought in disciplined formations forming barricades with their shields to protect lines and groups of men. (a tortoise)
  The metal “boss” in the centre of the shield could be used as a weapon.
  The shields were decorated with wings and lightning bolts to praise Jupiter the Roman god of the army.
  The Legions used oblong shields and the auxillia and cavalry used oval ones.