Bat

Part of the Extreme Mammals exhibition.

As much as we know about bats and how they get around, the answer to a long-time bat mystery comes from Wyoming, circa 52 million years ago. Did bats first fly, or echolocate--that is, use sound to navigate and feed at night?

The fossil bat, Onychonycteris finneyi, provides clear evidence that flying came first. The skull and bones of this fossil lack known adaptations for echolocation, but its skeleton, including its already elongated finger bones, reveals that it had wings and could definitely fly.

Fun Facts

  • The smallest mammal alive today is the bumblebee bat. Found only in Thailand and Myanmar, the bumblebee bat is no bigger than a bee and weighs only about as much as a dime. The tiny bat beats its wings so fast that it can hover in place like a hummingbird and is so rare that it was unknown to science until 1974.
  • Some bats can walk. Vampire bats, for instance, often crawl undetected onto the bodies of their sleeping prey to bite them and sip their blood.
  • Researchers believe that Anoura fistulata, the nectar bat from Ecuador, is the only bat that can pollinate the flowering plant, Centropogon nigricans.
  • The Mexican free-tailed bat is the fastest flying mammal with a top speed of 60 miles per hour (97 kph).

Current Research

The evolutionary history of bats has not been completely resolved. Nancy Simmons of the American Museum of Natural History and other scientists are gradually unearthing their early evolutionary origins. Research suggests that flying bats might have evolved from a wingless, four-limbed ancestor. The proportions and anatomy of the spectacularly complete fossil bat, Onychonycteris finneyi, from Wyoming, reveals clues about the transition.

  • Claws on five fingers of each hand--a primitive mammal characteristic; modern bats lost several claws during evolution
  • Shorter front limbs than modern bats
  • Longer rear limbs than modern bats
  • Ratio of forelimbs' length to hindlimbs suggests that this specimen was transitional between non-flying mammals and bats
  • Very long fingers, like modern bats