What’s the smallest mammal that ever lived? The tiny creature namedBatodonoides vanhouteni was so small, it could have perched on a pencil. With an estimated body weight of just 1.3 grams less than a twentieth of an ounce it weighed only about as much as a dollar bill. It lived approximately 50 million years ago and is related to modern shrews and moles. Batodonoides was named by American Museum of Natural History paleontologist Michael Novacek.Also it's frigid cuteeee.