Tiny monkeys discovered in Amazon

Scientists working in Brazil's central Amazon have discovered two new species of monkey the size of kittens, according to a conservation group.

The monkeys were discovered by Marc Van Roosmalen, a Dutch scientist working at Brazil's National Institute for Amazon Research in Manaus, nearly 3,000 kilometres northwest of Rio de Janeiro. Mr. Van Roosmalen works in a little-explored region of the Amazon near the confluence of the Madeira and Tapajos rivers.

Descriptions of the monkeys, Callicebus bernhardi and Callicebus stephennashi, were published this week in the peer-review journal Neotropical Primates. The bernhardi monkey is remarkable for its dark orange sideburns, chest and inner limbs. It has a reddish-brown back and a white-tipped black tail.

The stephennashi is silver with a black forehead and red sideburns, chest and inner limbs. It measures about 28 centimetres, with a 43-centimetre tail. On average, the monkeys weigh about 680 grams.

"This once again demonstrates how little we know about biodiversity, these are the 37th and 38th new primate species described since 1990," said Russell Mittermeier, the group's president and co-author of the report.