 Archaeoindris fontoynontii is an extinct giant lemur and the largest primate known to have evolved on Madagascar , comparable in size to a male gorilla . It belonged to a family of extinct lemurs known as " sloth lemurs " ( Palaeopropithecidae ) , and because of its extremely large size , it has been compared to the ground sloths that once roamed North and South America .
 nobody knows what the sloth lemurs ate , but it is possible that the Fontoynontii may have been a fruit eater.
The first specimen of the species was discovered in 1912 in the limestone caves of Ranomafana , Mad