Conservation International announced today the discovery of two new species of titi monkey in Brazil’s Amazon rain forest. The findings are published in a just-released special supplement to the journal Neotropical Primates. They were described by Marc van Roosmalen, a primatologist at Brazil’s National Institute for Amazon Research (INPA), his son, Tomas van Roosmalen, and Russell Mittermeier, president of Conservation International and chair of the World Conservation Union (IUCN) Species Survival Commission’s Primate Specialist Group. "Even though our closest living relatives, the primates, have been very well-studied for the past four decades, we are once again surprised by the discovery of even more species," said Mittermeier. "It proves how much we still need to learn about biological diversity, especially in the tropical rainforests." One of the species, Callicebus bernhardi, or Prince Bernhard’s titi monkey, is remarkable for its dark orange sideburns, chest and the inner sides of its limbs, its reddish-brown back, and a white-tipped black tail. It lives between the east bank of the Rio Madeira and the lower reaches of its tributary, the Rio Aripuaña, south of the Amazon River. Callicebus bernhardi is named for His Royal Highness Prince Bernhard of the Netherlands, a noted naturalist who created the Order of the Golden Ark to honor conservationists internationally. This prestigious award was bestowed upon co-authors Marc Van Roosmalen and Russell Mittermeier in recent years. Van Roosmalen will present the discovery to the Prince at Soestdijk Palace in Holland on June 25, four days before the Prince’s 91st birthday. Prince Bernhard will also receive a special portrait of his monkey by Stephen Nash, CI’s technical illustrator, who has made major contributions to primate conservation worldwide through his posters and educational materials. The second new species, Callicebus stephennashi, is named after Nash, who works for Conservation International and is based at the Department of Anatomical Sciences at the State University of New York at Stony Brook.