The Anatomy of a Giant
Megaladapis was a genus of giant lemur unlike any primate alive today. The largest of its three species, Megaladapis edwardsi, weighed an estimated 85 kilograms (187 pounds) and measured up to 1.5 meters (nearly 5 feet) in length, comparable in size to a male orangutan. Its body was robust and koala-like, with long arms, short legs, and large hands and feet adapted for powerful gripping on tree trunks and branches. This anatomy made it a slow, deliberate vertical climber, but likely awkward and inefficient on the ground.
The skull of Megaladapis is distinctive. Reaching up to 25 centimeters in length, it was elongated with a tapering snout, reminiscent of a calf than a primate. A prominent sagittal crest ran along the top of the cranium, anchoring massive jaw muscles needed to chew tough, fibrous leaves. Unlike other primates, its eyes were positioned on the sides of its head, and it lacked upper incisors, possessing instead a tough, horny pad for cropping vegetation. Despite its large body, Megaladapis had a small brain, with a brain capacity of about 250 cubic centimeters, only three to four times that of a domestic cat.
Extinction of a Mega-Lemur
Subfossil remains indicate that Megaladapis roamed the wooded habitats of Madagascar until relatively recently. Radiocarbon dating of bones shows the last populations survived until approximately 500 to 600 years ago, with the final extinction occurring between 1280 and 1420 AD. This timeline confirms that Megaladapis coexisted with humans on the island for over a millennium.
The arrival of humans around 2,300 years ago initiated a wave of megafaunal extinctions across Madagascar. The disappearance of Megaladapis was likely caused by a combination of pressures. Humans cleared large areas of forest for agriculture using "slash-and-burn" techniques, drastically reducing the lemur's specialized habitat. Fossil bones showing cut marks suggest that these large, slow-moving animals were also hunted for bushmeat. A major drought around 1,000 years ago may have exacerbated these pressures, leading to crop failures and increased reliance on hunting by human inhabitants.