Original: The Etruscan Shrew (Suncus etruscus) , also known as the Etruscan Pygmy Shrew or the White-toothed Pygmy Shrew is the smallest known mammal by mass, weighing only about 2 grams, although the smallest known mammal by skull size is the Bumblebee Bat.
Simplified: The Etruscan Shrew (Suncus etruscus) , also known as the Etruscan Pygmy Shrew or the White-toothed Pygmy Shrew is the smallest known mammal by mass.