Archaeolemur is a genus of two species of lemur that became extinct around 1,100 to 900 years ago. With fossils found copiously in present-day Madagascar, the archaeolemur was a quadruped lemur adaptation that divided its time between the ground and the tree branches and fed mostly on seeds and insects.
The distinctive feature of the archaeolemur was its stronger-than-average jaws and prominent teeth, which it used to crack shells and seed covers in order to get at the flesh inside. It also differed from other lemurs in having a thicker, stouter body, shorter limbs, and smaller hands.
The archaeolemur spent roughly three-quarters of its time on the ground but was capable of brachiation. It was an omnivore that sometimes consumed insects such as ants, but mostly fed on plant matter. It was about the same size as today's lemurs.
Archaeolemur went extinct because of environmental changes and the spread of human civilization, which overran its habitat. Archaeolemur lived in the grasslands of central Madagascar and was well adapted to the savannah.
A 2005 report on recent findings of complete sets of Archaeolemur hand bones states that Archaeolemur had extremely small hands for its species, so that it was likely not able to manipulate objects with much dexterity. In this way it was more similar to most quadrupeds than it is to most lemurs and monkeys. Tool use among Archaeolemurs was highly unlikely.
A 1994 report on Archaeolemur's jaw and tooth structure suggests that Archaeolemur likely had powerful jaws that were not fully developed while it was immature. The jaws and teeth were primarily suited to cracking shells and pods. One of the reasons Archaeolemur became extinct might be that its main food supply of hard-shelled seeds dried up with increased human cultivation of land.
There is an ongoing study that uses computer graphic simulation of Archaeolemur skulls in order to determine the level and type of force exerted by Archaeolemur's jaws, in an attempt to confirm the theory, currently based on fossil observation, that Archaeolemur fed heavily on the meat inside hard-shelled nuts. The Archaeolemur skull models are being compared to the models of another small mammal, Hadropithecus stenognathus, which is believed to have eaten grass seeds with its smaller and weaker teeth, and which went extinct about 1,300 to 1,600 years ago.
Archaeolemur is distinguished from other, related species by its prominent upper incisors, which overlapped its lower incisors.