New fossils reveal humanity's mysterious lost 'cousin'

DNVN - Fossils recently discovered in northeastern Ethiopia, dating from 2.6 to 2.8 million years ago, are opening up new insights into human evolution.

Newly discovered teeth in Ethiopia suggest early humans coexisted with a mysterious relative, reshaping our understanding of human origins. Source: Shutterstock.

Shocking discovery from the Ledi-Geraru Project

An international research team led by Arizona State University (ASU) scientists has found evidence that Australopithecus and early members of the genus Homo lived at the same time and in the same place in the Ledi-Geraru region. Among them is a completely new species of Australopithecus, never before identified.

Notably, this is also the place where the world’s oldest Homo specimens were discovered, along with primitive Oldowan stone tools. This time, the research team found 13 Australopithecus teeth, which through analysis confirmed to be a separate species, completely different from Australopithecus afarensis - the species of the famous fossil “Lucy”.

Thirteen fossil teeth were collected at the Ledi-Geraru Study Area between 2015 and 2018. Collections at sites LD 750 and LD 760 represent a newly discovered species of Australopithecus. LD 302 and AS 100 represent early Homo species known from the lower jaw bone LD 350 discovered in 2013. Credit: Brian Villmoare/University of Nevada, Las Vegas

Paleoecologist Kaye Reed (ASU), co-director of the Ledi-Geraru Project since 2002, emphasized: “This discovery shows that human evolution did not proceed in a linear fashion as many people imagine. Instead, it resembled a dense tree with many extinct branches.”

Teeth - the "golden clue" of human ancestors

The new discovery builds on a legacy from 2013, when Reed’s team announced the oldest Homo jawbone fossil, dating back 2.8 million years. This time, fossil teeth from 2.6-2.8 million-year-old sediments add to the evidence that Homo was indeed very early.

“These are the teeth from Turtle Flat as we discovered them – you can see what the ground looked like behind them, and it was amazing that Omar Abdulla saw them on the surface for the first time,” said Amy Rector, a scientist at Virginia Commonwealth University. Source: Amy Rector, Virginia Commonwealth University

“We know what the teeth and jaws of early Homo looked like, but that’s about it,” said lead author Brian Villmoare. “More fossils are needed to better differentiate between Australopithecus and Homo, and understand how they coexisted in the fossil record.”

Still, the team has been unable to scientifically name this new Australopithecus species based on the teeth alone.

University of Arkansas associate professor Lucas Delezene compares one of the incisors the team discovered with an Australopithecus upper molar from Hadar at the National Museum of Ethiopia. Credit: Amy Rector

“Volcanic clock” determines age

The fossils were dated using ash from volcanic eruptions in the Afar Fault Zone. The ash contained feldspar crystals, allowing geologists like Christopher Campisano (ASU) to pinpoint the time.

“These fossils are interspersed between layers of volcanic ash, so we can date the upper and lower layers, thereby confirming the age of the fossils,” Campisano explains.

The Ledi-Geraru paleontology team is searching for fossils in the Lee Adoyta Basin, where the genus Homo and Australopithecus were discovered. Credit: Kaye Reed, Arizona State University

Today, Ledi-Geraru is a dry, fractured landscape. But millions of years ago, it was home to rivers, vegetation, and shallow lakes that periodically expanded. This suggests that the environment was suitable for multiple hominin species to coexist.

Map showing (left) the location of the Ledi‑Geraru site in the Horn of Africa and (right) the locations of the Australopithecus and Homo teeth. Source: Erin DiMaggio

“The geology of the area allows us to pin down the exact date of the 2.3-2.95 million year period, which is a significant milestone for human evolution,” added ASU geology professor Ramon Arrowsmith.

From left to right: Arizona State University Professor Ramon Arrowsmith, Chancellor's Professor Emeritus Kaye Reed, and Associate Professor Christopher Campisano discuss Homo teeth found at Asboli, a site at the Ledi-Geraru site. Photo: Eric Scott

Many unsolved mysteries

The team is analyzing tooth enamel to learn more about the diet of the new Australopithecus species. They ask: Did early Homo and the yet-to-be-identified Australopithecus eat the same foods? Did they compete or share resources? Did they meet daily?

“Every discovery shows that we need more fossils,” Reed said. “Only then can we tell the full story of our ancestors. But because we are the survivors, we know for sure that the evolutionary journey led to where we are today.”

La Khe (According to SciTech Daily)

Source: https://doanhnghiepvn.vn/cong-nghe/hoa-thach-moi-tiet-lo-nguoi-anh-em-ho-bi-an-da-mat-cua-loai-nguoi/20250829061310701