Life in Leaf Litter: Finding Tiny Frogs

A photograph of Paedophryne amanuensis (LSUMZ 95004) on a U.S. dime (diameter 17.91 mm). CREDIT: Christopher Austin, LSU View full size image

This Research in Action article was provided to LiveScience in partnership with the National Science Foundation.

The world's tiniest known vertebrate species — was recently discovered by Louisiana State University's Chris Austin — is a tiny frog averaging measuring in at less than 0.3 inches (only 7.7 millimeters) in length.

It boots Paedocypris progenetica, an Indonesian fish averaging a little over 0.3 inches (more than 8 mm), from the top of the tiny charts.

Austin, leading a team of scientists from the United States including graduate student Eric Rittmeyer, also from Louisiana State University, made the discovery during a three-month long expedition to the island of New Guinea, the world's largest and tallest tropical island.

As a curator of herpetology (the study of amphibians) at The LSU Museum of Natural Science and associate professor of biological sciences, Austin is no stranger to discovering new species, having described numerous species previously unknown to science, including frogs, lizards and parasites.

Austin's work, supported by the National Science Foundation, highlights an interesting trend among the discovery of extremely small vertebrates.

"The size limit of vertebrates, or creatures with backbones, is of considerable interest to biologists because little is understood about the functional constraints that come with extreme body size, whether large or small," said Austin.

With more than 60,000 vertebrates currently known to man, the largest being the blue whale with an average size of more than 75 feet (25 meters) and the smallest previously being the small Indonesian fish averaging around .3 inches (8 mm), there was originally some thought that extreme size in vertebrates might be associated with aquatic species, as perhaps the buoyancy offers support and facilitates the development of extremism. However, both new species of frogs Austin described are terrestrial, suggesting that living in water is not necessary for small body size.

"The ecosystems these extremely small frogs occupy are very similar, primarily inhabiting leaf litter on the floor of tropical rainforest environments," said Austin. "We now believe that these creatures aren't just biological oddities, but instead represent a previously undocumented ecological guild — they occupy a habitat niche that no other vertebrate does."

For more information about Austin's research lab, visit www.museum.lsu.edu/Austin/Lab.html.

To learn more about the LSU Museum of Natural Science, visit www.lsu.edu/museum.

Editor's Note: Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation. See the Research in Action archive.