ABSTRACT
An invasion of Madagascar directly from the Asian mainland and an introduction from Asia by way of India seem equally unlikely in view of the vast distances involved. Perhaps a more important consideration is that the Paleocene Eurasian fauna contains no primates which may plausibly be regarded as sister groups of any of the Malagasy lemurs besides Lemuridae. Archaeolemurinae is an indriid subfamily containing three species Archaeolemur majori, A. edwardsi, and Hadropithecus stenognathus. The most striking departures of the archaeolemurines from the ancestral indriid condition, most closely approximated by Propithecus, are an increase in size and specialization of the masticatory apparatus. The primary characteristic distinguishing the palaeopropithecines from the indriids lies in the construction of the middle ear. Instead of possessing the "lemuroid" condition, with the tympanic ring free inside an inflated bulla, the palaeopropithecines lack the latter and the ectotympanic communicates with the exterior via a bony tube.
