At one time many years ago, gigantic lemurs the size of humans roamed around Madagascar. According to the IUCN, there are 113 known lemur species native to Madagascar with the Indri being the largest, growing as long as 24 to 35 inches (between 2 and 2.9 feet) and weighing between 6 and 10 kilograms (between 13 and 22 pounds). While there are still over 100 lemur species currently living in Madagascar, the largest ones became extinct between 500 and 2,000 years ago.
Koala lemurs (Megaladapis edwardsi) grew as long as 1.5 meters (5 feet) and weighed approximately 85 kilograms (187 pounds). Interestingly, despite their large size, their diet consisted of leaves. And they weren’t the only large ones as at least 17 giant lemur species inhabited Madagascar at one time.
Unfortunately, DNA doesn’t usually remain preserved for long in tropical and sub-tropical climates, but recently that all changed as scientists were able to study hundreds of extinct lemur bones and actually recovered genetic materials. They found DNA on a 1,475-year-old jawbone belonging to a koala lemur and they were able to do nuclear genomic analysis on it (the reconstruction of its genome from DNA found in the nucleus of the cell which will then give experts genetic data from the species’ parents).
Stephanie Marciniak, who is a postdoctoral scholar in the Department of Anthropology at Penn State University, explained this further in an email to Live Science, “The nuclear genome has thousands of independent markers of ancestry compared to the mitochondrial genome, so it’s well-suited to definitively address the relationship of Megaladapis to other lemurs.” The researchers compared the ancient DNA to today’s lemurs and found that the koala lemurs were closely related to red-fronted lemurs (Eulemur rufifrons).
Another interesting discovery was that when the koala lemur’s DNA was compared to that of 47 non-lemur animals, they found that golden snub-nosed colobine monkeys (Rhinopithecus roxellana) and horses (Equus caballus) had similar protein-encoding genes as the lemur. The genes aid the animals to break down toxins in leafy plants as well as absorb nutrients.
As for why it was only the giant lemurs that disappeared, Marciniak, explained, “It was the large-bodied species that predominantly became extinct, rather than smaller species that existed at the same time.” “The habitats that the giant lemurs were adapted to likely changed substantially, impacting their ability to survive.” The study was published in the journal Proceedings of the National Academy of Sciences.
Pictures of the skull and of what the Megaladapis edwardsi (koala lemur) would have looked like can be seen here.