Smallest vertebrate in the world found in Papua New Guinea: Frog measures just 7mm

By Tamara Cohen


Perched on a coin the size of a 5p piece, there is still probably room for two.

At half the size of a Smartie sweet, this is the world’s smallest frog, measuring just a quarter of an inch long.

Scientists discovered the previously unknown creature, speckled in red and black, sitting on a leaf on the tropical island of Papua New Guinea.

Miniscule: This tiny frog, believed to be the smallest vertebrate on Earth, has been discovered by scientists in Papua New Guinea

At just 7.7mm in size when fully grown, it has snatched the title as the smallest of the world’s 60,000 vertebrates – creatures with a backbone – previously held by a tiny Indonesian fish which measures 7.9mm.

Experts are baffled by the find as it was previously thought extreme body size in vertebrates, whether large or small, was associated with living in water.

Professor Chris Austin, of Louisiana State University, who discovered the frog on a three-month field trip to the Pacific island, said by contrast these creatures make their habitats on fallen leaves on the floor of tropical rainforests.

His discovery of the creatures, named Paedophryne amanuensis after a village called Amau near where they were found, will help scientists understand more about extreme body size, he wrote in the journal PLoS One.

They are thought to have evolved ‘extreme miniaturisation’ to fill a hole in the food chain which was not being exploited by others, perhaps to eat minuscule creatures such as mites which would not sustain larger frogs.

It was no easy job to find one, but his team followed the high-pitched calls made by adult males when they are looking for a mate.

The tiny specimen fits comfortably on a US dime, which measures 17.9mm, slightly smaller the size of a 5p piece which measures 18mm.

Prof Austin said: ‘We now believe they aren’t just biological oddities, but instead represent a previously undocumented ecological guild - they occupy a habitat niche that no other vertebrate does.

‘It was particularly difficult to locate Paedophryne amauensis due to its diminutive size and the males’ high pitched insect-like mating call. ‘But it’s a great find.

New Guinea is a hotspot of biodiversity, and everything new we discover there adds another layer to our overall understanding of how biodiversity is generated and maintained.’


Tiddler: Paedocypris progenetica, a tiny fish discovered in the peat swamps of Indonesia and measuring 7.9mm was previously thought to be the world's smallest vertebrate


Distant cousin: The largest of the world's 60,000 vertebrates, the blue whale, measures around 26m

The Louisiana team, from the university’s Museum of Natural Sciences, also found a second new and slightly larger frog which they called Paedophryne swiftorum and measures 8.3 - 8.9 mm.

Tiny frogs tend to life in rainforests because their small bodies are particularly susceptible to water loss, and scientists cannot rule out finding an even smaller one there one day.

Biologists are very interested in why vertebrates vary so much in size, with the world’s largest, with an adult blue whale measuring around 26m.

Until now the smallest was Paedocypris progenetica, a tiny transparent fish related to the carp found off Sumatra in Indonesia.


source:dailymail