09/11/2026
Wild monkeys in West Africa have been observed climbing vertical tree trunks using a degree of foot flexibility that researchers did not realise they possessed. The finding challenges a key assumption used to interpret fossil feet in human evolution.
Fossil foot bones are heavily used to reconstruct how extinct primates and early human relatives moved. If a foot looks rigid and adapted for walking, researchers infer the animal spent its time on the ground. If it looks flexible and grasping, they infer tree climbing. That interpretation depends on knowing what real feet are actually capable of.
These monkeys demonstrate more capability than their bone structure alone would suggest. They can perform demanding vertical climbing using flexibility that would not necessarily be predicted from studying their skeletons.
That has direct consequences for how we read the fossil record. If living primates can do more than their bones imply, then extinct species may also have been more versatile than their fossils suggest. Assumptions about when human ancestors stopped climbing trees may need revisiting.
Bones only tell part of the story. How much of what we believe about how our ancestors moved is built on what their skeletons appear to allow?
(Source: ScienceDaily, August 31, 2026 / Primatology)