This Mysterious Gliding Mammal Is a 'Sister' to Primates

By Mindy Weisberger, Senior Writer | August 10, 2016 03:06pm ET

Gliding mammals called colugos sail through the air using membranes that stretch between their limbs and resemble the wings of bats. But these furry gliders are actually a sister group to primates, a new study finds.

Colugos are tree dwellers, with limbs connected by flaps of skin known as a patagium, or gliding membrane. These critters live in southeast Asia, and adults measure about 14 to 16 inches (35 to 40 centimeters) long and weigh around 2 to 4 lbs. (1 to 2 kilograms).

Scientists have debated colugos' lineage for the past century. Some experts had linked them to tree shrews, with which colugos share certain physical traits. But recent genetic sequencing revealed that colugos are more closely related to primates — the group that includes great apes and humans. This finding could help scientists develop a clearer picture of evolution in the earliest primates, the researchers suggested.

There are only two known colugo species — sometimes referred to as "flying lemurs," though they are not lemurs and do not fly — and they are poorly understood for a number of reasons, according to study co-author William Murphy, a professor in the Department of Veterinary Integrative Biosciences at Texas A&M University.

Colugos' unusual gliding adaptations have hampered efforts to keep them in captivity, Murphy told Live Science in an email. And their nocturnal lifestyle high in the tree canopies makes it difficult for scientists to observe and track them in the wild.

"Only a few publications have documented their [colugos'] ecology and habits," Murphy said.

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