swimmer that fed on mollusks and crustaceans while concealed underwater. It was primarily the paleontologist Charles Lamberton who correctly paired many of the confused subfossils, although others had also helped address problems of association and taxonomic synonyms. Lamberton also refuted Guillaume Grandidier's sloth theory for Megaladapis, as well as the aquatic lemur theory of Standing and Sera. Excavations during the early 20th century by researchers like Lamberton failed to unearth any new extinct lemur genera. Fourteen of the approximately seventeen known species had previously been identified from field work in southern, western, and central Madagascar. When paleontological field work resumed in the early 1980s, new finds provided associated skeletal remains, including rare bones such as carpal bones (wrist bones), phalanges (finger and toe bones), and bacula (penile bone). In some cases, nearly complete hands and feet were found. Enough remains have been found for some groups to demonstrate the physical development of juveniles. Standard long-bone indices have been calculated in order to determine the intermembral index (a ratio that compares limb proportions), and body mass estimates have been made based on long-bone circumference measurements. Even preserved fecal pellets from Archaeolemur have been found, allowing researchers to learn about its diet. More recently, electron microscopy has allowed researchers to study behavioral patterns, and DNA amplification has helped with genetic tests that determine the phylogenetic relationships between the extinct and living lemurs. A new genus of sloth lemur, Babakotia, was discovered in 1986 by a team led by Elwyn L. Simons of Duke University in karst caves on the Ankarana Massif in northern Madagascar. Along with Babakotia, a new species of Mesopropithecus, M. dolichobrachion, was also discovered, but not formally described until 1995. The same team has also helped promote new ideas about sloth lemur adaptations and the relationships among the four genera. They have also provided evidence that living species, such as the indri and the greater bamboo lemur, have lost much of their original range. In 2009, a new species of large sloth lemur, called Palaeopropithecus kelyus, was described from northwestern Madagascar by a Franco-Madagascan team. The new species was found to be smaller than the two previously known species from the genus, and its diet reportedly consisted of more hard-textured food. The resurgence in subfossil lemur work has also sparked new interest in Madagascar's small mammals, which have also been found at the subfossil sites. This has led to