Mysterious Fossil Foot Belonged to Ancient Human that Lived Alongside ‘Lucy’

Mysterious Fossil Foot Belonged to Ancient Human that Lived Alongside ‘Lucy’

By Humberto Basilio edited by Claire Cameron

Sixteen years in the past a group of anthropologists found 3.4-million-year-old fossilized foot bones in Ethiopia. While they suspected the foot belonged to an historical human that possible lived alongside the species we all know as “Lucy,” Australopithecus afarensis, with no cranium or tooth to research, they couldn’t make sure.

What they did know is that not like Lucy, which walked upright on arched toes like our personal, the thriller foot had a greedy toe that was tailored for climbing bushes.

Now the identical staff that found the unusual foot have lastly solved the thriller. In a paper revealed Wednesday in Nature, the researchers describe other hominin fossils found in the same area because the appendage, which they nicknamed the Burtele foot. The findings verify that Lucy lived alongside one other hominin species known as Australopithecus deyiremeda, which behaved fairly otherwise from its A. afarensis friends.

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“It’s a really exciting discovery long-awaited for all of us who have been wondering what that crazy foot was,” says University of Missouri anthropologist Carol Ward, who was not concerned within the new examine.

“Not only do we have different species living at pretty similar times in a similar area but they are navigating the world in a different way from one another,” she says.

Anthropologists had suspected that the Burtele foot belonged to A. deyiremeda for years: In 2015 they reported the species’ existence within the area based mostly on jawbones that had been 3.5 million to three.3 million years outdated. But to conclusively hyperlink A. deyiremeda to the Burtele foot, the staff wanted to return to its discovery website to search out extra fossils.

“We have been going to the site every year for 20 years now, and the Burtele locality is revisited every year like every locality at the site,” says Arizona State University paleobiologist and examine co-author Yohannes Haile-Selassie.

During the latest go to to Ethiopia’s paleoanthropological website Woranso-Mille, the staff made a number of pivotal discoveries: fragments of pelvic bones and, crucially, a cranium and a jawbone with 12 tooth. Identified as belonging to A. deyiremeda based mostly on the form of the canines and molars, the jaw confirmed extra primitive options than its A. afarensis cousins.

After analyzing the tooth, the staff discovered that their proprietor ate a unique food plan to Lucy, preferring to eat bushes, shrubs, fruits and leaves—a food plan extra much like extra historical hominins, in accordance with the staff. By distinction, Lucy’s species usually ate vegetation from combined woodland areas and grassland vegetation.

The Burtele foot provides clues to how A. deyiremeda managed to deftly climb bushes for sustenance: its lengthy, curved toes and versatile bones counsel a foot effectively tailored for scaling and holding on to bushes. Even the bones of the massive toe are slender and curved, suggesting it might wrap round branches.

By combining their finds—the tooth, the dietary evaluation and the foot—and considering the absence of different hominin fossils on the website, the scientists have concluded that the mysterious Burtele foot belonged to A. deyiremeda.

The discovering provides researchers extra alternative to study how historical people tailored to stroll upright, Haile-Selassie says. And, he says, it reveals that not all human ancestors walked on two toes.

“It is a unique mode of locomotion that underwent various experiments throughout human evolution until the emergence of Homo,” he says.

It might additionally assist settle one other debate as soon as and for all: the 2015 discovery of A. deyiremeda was contested, with some scientists arguing the specimens really belonged to A. afarensis, says paleoanthropologist Donald Carl Johanson, who found Lucy in 1974.

The new examine as an alternative means that A. deyiremeda inherited its foot traits from an ancestral species completely different from that which gave rise to Lucy’s sort, Johanson says. “Acceptance of a new hominin species always attracts criticism,” he says. “Whether the new evidence will convince a wider audience that A. deyiremeda is a valid species remains to be seen.”

Knowing that one other hominin lived alongside Lucy’s species additionally challenges the concept human evolution was comparatively linear, Ward says. The new findings additionally pose questions on how historical hominins walked.

Haile-Selassie’s staff will proceed returning annually to the Burtele website to study extra in regards to the biology and geographic distribution of A. deyiremeda. “There are many questions that we can ask about this species,” Haile-Selassie says.

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