Hold onto your hats, because the story of human evolution just got a whole lot more complicated—and fascinating. A mysterious fossilized foot discovered in Ethiopia has finally found its owner, and it’s not who we expected. This ‘mystery foot,’ unearthed in the Afar Region in 2009, has long puzzled scientists. But here’s where it gets even more intriguing: it belongs to a little-known human relative named Australopithecus deyiremeda, who lived alongside the famous Lucy (Australopithecus afarensis) over 3 million years ago. And this is the part most people miss—this discovery could shake up our understanding of who our direct ancestors really were.
The foot itself is a game-changer. Unlike Lucy’s species, it features an opposable big toe, much like a thumb, which allowed its owner to grip tree branches like an ape. This detail alone suggests a lifestyle far more arboreal than Lucy’s, who was thought to be fully adapted to walking on two legs. But why does this matter? Because it challenges the long-held belief that Lucy’s species was the only human relative in the area at that time—and possibly the sole contender for the title of our direct ancestor.
The team behind this discovery first introduced A. deyiremeda in 2015, based on jawbones found in Burtele, Ethiopia. However, their announcement was met with skepticism, as adding a new branch to the human family tree is no small feat, especially with limited fossil evidence. At the time, they couldn’t definitively link the ‘Burtele foot’ to this new species. Fast forward to today, and a study published in Nature has finally connected the dots. New fossils, including a jawbone with 12 teeth, confirm that the foot belongs to A. deyiremeda.
‘We have no doubt about the Burtele foot belonging to the same species as these teeth and the jaw,’ said lead researcher Yohannes Haile-Selassie of Arizona State University. This breakthrough not only validates A. deyiremeda’s existence but also paints a richer picture of our ancient past. CT scans of the teeth reveal that this species was more primitive than Lucy, while isotope analysis shows a diet of leaves, fruits, and nuts—further evidence of a tree-dwelling lifestyle.
But here’s the real kicker: How did two such different species coexist in the same place and time? The answer lies in their ecological niches. A. deyiremeda likely spent most of its time in the forest, while Lucy’s species was more grounded. This division of habitats allowed them to thrive side by side, proving that ‘co-existence is deep in our ancestry,’ as Haile-Selassie aptly put it.
This discovery has already sparked debate among experts. John McNabb, a paleolithic archaeologist at the University of Southampton, believes these findings will help researchers accept A. deyiremeda as a legitimate player in the story of human evolution. While it’s unlikely to replace Lucy as the prime candidate for our ancestor, it opens the door to a tantalizing possibility: Could there be other undiscovered species from this era that better fit the bill?
Haile-Selassie himself raises this question, suggesting that early Australopiths were ‘experimenting with bipedality.’ So, the hunt continues. As we dig deeper into our past, one thing is clear: the tree of human evolution is far more complex—and fascinating—than we ever imagined. What do you think? Could A. deyiremeda or another unknown species be the true ancestor of Homo sapiens? Share your thoughts below!