Petter-Rousseaux and Petter, 1967
The genus Allocebus consists of only one species, Allocebus trichotis (Günther, 1875; Günther pl15), which externally highly resembles a Microcebus. It is a rare species, of which biology is very little known.
Systematic research (Petter and Petter-Rousseaux, 1956) permitted the discovery of two specimen of Malagasy lemurs, in the collections of the 'Muséum National d'Histoire Naturelle, Paris'. They were determined as Cheirogaleus trichotis (Günther, 1875); a young and an adult, but with incomplete skull. Apart from these two specimens (collected by Humbolt around 1880) only the type specimen preserved in the British Museum of Natural History is known. There is no exact information about the place of capture of these animals since Humbolt never returned from his second journey to Madagascar.
In 1965, Peyriéras sent a Cheirogaleus trichotis, originating from the region of Mananara, in the east of Madagascar, which he could keep in captivity for some days. This lemur with nocturnal habits was captured in a tree-hole.
Considering the external characters and certain anatomically particularities it was necessary to change the systematic position of this animal. A. trichotis is distinguished by its general appearance from both Cheirogaleus and from Microcebus and Phaner. By its dental characteristics (skulls Cheirogaleidae) Allocebus is clearly more related to Phaner and less to Cheirogaleus and Microcebus. However it differs from Phaner by the shape of the mastoid region. Therefore it seems justifiable to place it in a new genus (Petter and Petter-Rousseaux, 1967).