The Aquilifer reference article from the English Wikipedia on 24-Apr-2004
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Aquilifer

An aquilifer was the standard bearer of a Roman legion. The name derives from the type of standard, aquila meaning "eagle", which was the universal type used since 104 BCE; before that time the wolf, boar, and horse were also used. The standard was the most important possession of the legion and its loss was a terrible disgrace. The aquilifer's position was accordingly one of enormous prestige. The aquilifer typically wore as headdress the hide of a leopard, wolf, bear, or, in the case of the Praetorian Guard, a lion; the animal's upper jaw would be on top of the helmet. He carried a small circular shield called parma that could be strapped on if his hands were already full with the standard and a weapon.