Wednesday, January 24, 2007

New Cloud-Forest Rodent Discovered

A distinctive new cloud-forest rodent (Hystriocognathi: Echimyidae) from the Manu Biosphere Reserve, Peru. 2007. B.D. PATTERSON and P.M. VELAZCO. MASTOZOOLOG√ćA NEOTROPICAL 13(2)
A strikingly unusual large rodent related to spiny rats was recently discovered in the cloud-forests of Peru.

Isothrix barbarabrownae by Nancy Halliday, The Field Museum

The nocturnal, climbing Isothrix barbarabrownae is beautiful yet strange looking, with long dense fur, a broad blocky head, and thickly furred tail. A blackish crest of fur on the crown, nape and shoulders add to its distinctive appearance.

I. barbarabrownae belongs to a family of rodents known as "spiny rats" because most of the species in that family bristle with spines. Its discovery has necessitated a re-examination of this tropical American family, especially its closest relatives, the bush-tailed tree rats found in South America's lowlands.

The authors of the study found the rodent in 1999 while conducting field research in Peru's Manu National Park and Biosphere Reserve Mountains in Southern Peru along the eastern slope of the Andes. Extending from lowland tropical forests in the Amazon Basin to open grasslands above the Andean tree line, Manu is home to more species of mammals and birds than any equivalently sized area in the world.

The new rodent was discovered at an altitude of 6,200 feet. Little is known about its lifestyle because subsequent efforts to locate and observe the animal were fruitless.

"The new species is not only a handsome novelty," Patterson said. "Preliminary DNA analyses suggest that its nearest relatives, all restricted to the lowlands, may have arisen from Andean ancestors. The newly discovered species casts a striking new light on the evolution of an entire group of arboreal rodents."

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