 The genus Mesopropithecus includes some of the smallest of the recently extinct subfossil lemurs , but all species were still noticeably larger than all living ( extant ) lemurs . They ranged in weight from 10 to 14 kg ( 22 to 31 lb ) . They were also the least specialized of the sloth lemurs , more closely resembling living indriids in both skull and postcranial characteristics . Skull length ranged from 93 @.@ 4 to 105 @.@ 5 mm ( 3 @.@ 68 to 4 @.@ 15 in ) . The dentition and cranial proportions , however , more closely resembled those of the sifakas . The dental formula of Mesopropithecus was the same as in the other sloth lemur and indriids : either 2 @.@ 1 @.@ 2 @.@ 31 @.@ 1 @.@ 2 @.@ 3 or 2 @.@ 1 @.@ 2 @.@ 32 @.@ 0 @.@ 2 @.@ 3 × 2 = 30 . Mesopropithecus had a four @-@ toothed toothcomb , like all indriids and most other sloth lemurs . It is unclear whether one of the permanent teeth in the toothcomb is an incisor or canine , resulting in the two conflicting dental formulae . Like other sloth lemurs and indriids , Mesopropithecus had rapid tooth development . 
