These swords are rather unique as they seem to fit into the category of a transition between the one hand sword and the rapier. They were conceived for combat at close range.
Their main characteristic is the crab shaped guard, in different variations.
They are extremely light and maneuverable.

Sword attributed to Pedro
Álvares Cabral, discovered Brasil, 1500.
Unearthed from his Tomb.

XVI Century Portuguese Sword. The guard shows a cross shaped hole. The pommel reminds the shape of a crown

XVI Century Portuguese Sword. Guard with the rounded and sharpened ends with the cross within.

First half of XVI Century Portuguese Sword.  The pommel shows a cross with a fleur-de-lis end. Variation of guard

Second Half of XVI Century Portuguese Sword.  The guard has been stylized but keeps the crab shape

Second Half of XVI Century Portuguese Sword.  Variation on the guard.