Penny-sized frogs are world's smallest
The frogs are so small they seem to have hit the lower limit of body size for frogs and toads, so it's unlikely that researchers will find anything much smaller.
The two new tiny frogs discovered in New Guinea, the tiniest in the world. The top frogs are examples of P. dekot and the lower two are P. verrucosa.
Fred Kraus, Bishop Museum, Honolulu
Smaller than a penny, two newly discovered frog species are considered the smallest ever found. The pipsqueaks live in Papua New Guinea and run about 0.4 inches (8-to-9 millimeters) in length.
The two species,聽Paedophrynedekot听补苍诲听Paedophryne惫别谤谤耻肠辞蝉补,听are not only聽, they are also the smallest of a group of animals called tetrapods (four-legged animals with backbones). The duo rounds out the聽Paedophryne聽genus, which already contained two other, slightly larger, frog species first described in 2002.
The name聽P. dekot聽derives from the word for "very small" in the local language, Daga, noted study researcher Fred Kraus in the Dec. 12 issue of the journal ZooKeys;聽P. verrucosa聽was named from the Latin for "full of warts," due to its distinctively lumpy skin.
P. dekot聽inhabits the lower ranges, below about 4,000 feet (1,200 meters) of the western slope of Mt. Dayman, in Milne Bay Province, Papua New Guinea, and聽P. verrucosa聽lives on the southeastern slope of 聽Mt. Suckling, near a region that joins Mt. Dayman.
"聽around the world," Kraus, of the Bishop Museum in Hawaii, said in a statement. "New Guinea seems particularly well represented, with species in seven genera exhibiting the phenomenon. Although most frog genera have only a few diminutive representatives mixed among larger relatives,聽Paedophryne聽is unique in that all species are minute."
The frogs are so small they seem to have hit the lower limit of body size for frogs and toads, so it's unlikely that researchers will find anything much smaller. The frogs are brown or red-brown in color, with聽聽of brown and blackish triangles on their sides.聽P. verrucosa聽has lots of wartlike protrusions on its skin, along with some yellow splotches.
Because of their tiny size, their聽聽are too small to allow much climbing, so they have found a niche on the forest floor, where their tiny body size allows them to hide among leaf litter and moss. The author suggests they might eat tiny arthropods, such as mites.
They are so small that females of both species can only have two eggs, limiting their ability to reproduce. Most frogs have lots of eggs per litter, so this small number is very rare. They also lose moisture very quickly, restricting them to very wet tropical forests.
The four known聽Paedophryne聽species inhabit small ranges in the mountains of southeastern Papua New Guinea and its offshore islands. Until their DNA is analyzed, researchers can't be sure who their closest froggy relatives are.
Kraus recorded the call the聽, which he notes sounds like "a quick drag of a finger over a comb." It makes its calls at dusk until the sky turns dark, and also before dawn.
The study of these tiny frogs was published Dec. 12 in the journal ZooKeys
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