For the first 100 years after the first aye-aye was brought to Europe in the 1780s, debate swirled. Was it a rodent, a primate, or most closely related to a kangaroo?
The root of this confusion lay in the aye-aye’s odd collection of behavioral and morphological traits that make it appear to be composed of spare parts of other animals: continuously growing front teeth, batlike ears, a foxlike tail, abdominal mammary glands, claws on most digits, and spindly, dexterous middle fingers.
In 1863, accomplished naturalist Sir Richard Own put the debate to rest: http://bit.ly/12HExKe
Pictured: A hand-painted lithograph from Monograph on the Aye-Aye, published in 1863 and written by Sir Richard Owen. The illustration is by Joseph Wolf.© AMNH/D. Finnin