Myanmar (formerly known as Burma) belonged to British colonial India in the early 20th century. British geologists working for the Geological Survey of India began exploring the paleontological potential of central Myanmar before the First World War. Their work in the Pondaung Formation, dated to the late Middle Eocene, unearthed an important mammalian fauna, including a primate, Pondaungia cotteri. Later, the work of the renowned American paleontologist Barnum Brown led to the discovery of a second fossil primate in the Pondaung Formation, Amphipithecus mogaungensis. Pondaungia, as well as Amphipithecus, were initially considered ancient members of the anthropoid lineage (which today includes apes, including great apes, and humans), although their anthropoid status was later disputed. Scientific exploration in Myanmar was suspended with the outbreak of the Second World War and the country's geopolitical isolation following its independence in 1948.
After decades of scientific quiescence, a new phase of exploration of the Eocene Pondaung Formation began in the late 1990s. This renewed activity led to the exhumation of a rich fossil fauna documenting the ancient primates of the Pondaung Formation, but without putting an end to scientific controversy. The new information obtained on Pondaung primates can be divided into two categories: firstly, we have greatly increased the number of species and higher-ranking taxa among the known primates of the Pondaung Formation. In addition to Pondaungia andAmphipithecus (two closely related genera that may, in fact, be just one taxon), we now know that central Myanmar was home to a small endemic radiation of amphipithecid primates, ranging in size from Pondaungia (approx. 9 kg) to Ganlea (approx. 2.5 kg) or Myanmarpithecus (approx. 1.8 kg). In addition to the amphipithecids, we also discovered fossil primates belonging to two other taxa, the lemur-like sivaladapids (represented by Paukkaungia and Kyitchaungia) and the eosimian anthropoid Bahinia.
