The as yet unnamed new species was found close to the border of Ecuador, said expedition co-leader Gerardo Ceballos, of the National Autonomous University of Mexico. Compared with two other species of night monkey in the region, the new one has a more uniform color and smaller skull.
This new species of small-eared shrew is still in the process of being named by Ceballos and his team. Much smaller than its relative the marsupial shrew, the small-eared shrew is an insect-eater distinguished by extremely small eyes and barely visible ears.
Tabaconas Namballe National Sanctuary's cloud forests provide shelter to at least 85 species of mammals, 326 species of birds, and 23 species of reptiles and amphibians—numbers that may grow as explorers delve deeper into the region.
The sanctuary contains a wide array of habitats—from rain forests to grasslands—condensed into roughly 70,000 acres (28,000 hectares), Ceballos said.
However, deforestation throughout much of South America may affect undiscovered species, Ceballos said.
"The habitat is very valuable," he said, "even without knowing the species that are there."