Two, New, Teacup-sized Species of Mouse Lemur Lookalikes Discovered in Madagascar

Two new species of mouse lemur have so much in common, it's impossible to tell them apart without genetic sequencing. Researchers discovered the new, teacup-sized species on the African island of Madagascar, and have now shown the new, tiny primates to the world.

The mouse lemurs are miniscule, only weighing about 2.5 to 3 ounces. With grey-brown fur and huge eyes, the primates are shy and nocturnal, blending in with the rainforest environment that they call home.

The first of the species is now named the Anosy mouse lemur, Microcebus tanosi. Despite being cousins to the grey mouse lemurs and the grey-brown mouse lemurs, the anosy mouse lemurs apparently don't interbreed with them. The other species has been dubbed the Marohita mouse lemur, Microcebus marohita, after the forest where it was found.

The lemurs were first discovered by researchers in 2003 and then 2007, when co-author Rodin Rasoloarison captured the two species. The researcher weighed and measured the tiny primates and took skin samples for genetic analysis in the lab. While the species looked similar on the outside, though, their DNA told another tale. Researchers analyzed two mitochondrial and four nuclear DNA genes in order to find out where the animals fit into the lemur family tree.

While these lemurs have been described for the first time only recently, though, they may not be around much longer. Rasoloarison returned to the location where he first found the Marohita mouse lemur, only to find that much of its forest home had been cleared.

"This species is a prime example of the current state of many other lemur species," said Peter Kappeler, one of the researchers, in a press release.

While mouse lemurs have thrived on the island of Madagascar for up to 10 million years, their populations are quickly declining. After the arrival of humans about 2,500 years ago, logging and slash and burn agriculture have taken their toll. Only about 10 percent of Madagascar's forests remain today, which makes lemurs the most endangered mammals in the world.

The description of the new species is part of an ongoing effort to catalogue and define these lemurs before they become extinct.

"Knowing exactly how many species we have is essential for determining which areas to target for conservation," said Kappeler.

The findings are published in the International Journal of Primatology.