A 52 million-year-old ankle fossil dug up in France shows the first primates were high flying acrobats in a find that could rewrite human history.
The shape and size of the tiny bone suggests our earliest ancestors flexed and sharply extended their ankles to launch themselves into the air.
For years, scientists believed the ancestors of today’s humans, monkeys and apes were relatively slow and deliberate.
But the new study found the first primates, which were about the size of a chipmunk, instead leapt through the trees.
A 52 million-year-old ankle fossil (pictured) shows the first primates were high flying acrobats in a find that could rewrite human history. The shape of the bone suggests our earliest ancestors flexed and sharply extended their ankles to launch themselves into the air
Paleontologists uncovered the bone, which measures just a quarter of an inch (63cm), while digging around a quarry near Marseilles, in southeastern France.
The fossil, which made up the lower part of a prehistoric creature’s ankle joint, came from the bizarre chipmunk-like Donrussellia provincialis.
Previously only known from jaw and teeth fossils, Donrussellia is thought be one of the earliest members of the primate family tree.
It sits on the evolutionary branch leading to lemurs, lorises and bush babies.
Professor Doug Boyer, of Duke University, North Carolina, and colleagues studied scans of the Donrussellia ankle bone and compared it to those of other animals.
Using computer algorithms to analyse the 3-D shape of the tiny bone, they were surprised to find Donrussellia’s ankle was not like those of other primates, but more similar to those of tree shrews and other non-primate species.
The animal did not just clamber or scurry along small branches, where it could reach flowers, fruits and insects.
Instead, it may have been able to bound between trunks and branches, using its grasping feet on landing.
Experts previously thought our early relatives used their grasping hands and feet to creep along branches to stalk insects or find flowers and fruits.
Professor Boyer said, contrary to what many scientists thought, the first primates may have evolved their acrobatic leaping skills earlier than first thought.
The anatomical changes that allowed them to cling to slender branch tips and creep from tree to tree came later.
The fossil, which made up the lower part of a prehistoric creature’s ankle joint, came from the bizarre chipmunk-like Donrussellia provincialis. It sits on the evolutionary branch leading to lemurs (file photo), lorises and bush babies
Professor Boyer said: ‘Being able to jump from one tree to another might have been important, especially if there were ground predators around waiting to snag them.’
Many biologists have argued the common ancestor of all primates was a small animal that scampered along thin tree branches.
Primates first appear in the fossil record about 57 million years ago and quickly divided into the ‘wet-nosed’ group that now include lemurs and the ‘dry nosed’ one represented by tarsiers, monkeys, apes and humans.
They each have common features including grasping hands and feet and nails rather than claws, implying they evolved in the same common ancestor.
Professor Boyer believes D. provincialis is the most primitive wet nosed primate discovered so far.
Primates first appear in the fossil record about 57 million years ago and quickly divided into the ‘wet-nosed’ group that now include lemurs and the ‘dry nosed’ one represented by tarsiers, monkeys, apes such as chimpanzees (file photo), and humans
The breakthrough is significant because recent discoveries suggest primitive dry nosed primates were also good leapers.
Archicebus achilles, described in 2013, had a long hindlimb and short forelimbs, which are characteristic of a leaping animal.
Professor Boyer said: ‘Donrussellia and Archicebus are definitely on opposite sides of the tree.
‘So when they both have the suggestion of leaping traits, it starts to look like acrobatic leaping behaviours were important early in primate evolution.’
If primates did begin as leapers, it will be harder to work out what drove their initial evolution.
Professor Boyer said: ‘It is easy to understand how specialisation for navigating small branches would be beneficial, specifically for harvesting food objects that grow there.
‘It is hard to think of a simple scenario that would emphasise acrobatic leaping on its own.’