Revision of Hapalemur (Prohapalemur) gallieni (Standing 1905)

Cranial and mandibular remains of the subfossil lemur Hapalemur (Prohapalemur) gallieni (Standing 1905) from Ampasambazimba in central Madagascar are reexamined and are shown here to belong to the rare but perhaps still extant species Hapalemur simus. Past descriptive errors and too limited comparisons have hampered previous taxonomic assessments of the three mandibular rami, two partial maxillae, and one partial cranium ascribed to H. (Prohapalemur) gallieni. These and other subfossil H. simus recently discovered at the Grotte d'Andrafiabe, Ankarana Massif (in the very northernmost part of Madagascar), and at the Grottes d'Anjohibe, near Mahajanga (northwest coast), show that H. simus was once extensively distributed on Madagascar. Records associated with 9 additional individuals in museum collections show that, at least until about 100 years ago, H. simus occupied much of the humid eastern forests of Madagascar, from the forests east of Fianarantsoa (where it lives today if it has not very recently become extinct) to as far north as "Passumbée' (Ampasimbe) which was located in the region of the Bay of Antongil. This paper reviews what is known of that distribution and the reasons for the taxonomic confusion surrounding the large species of Hapalemur.