Date:

Fossilized teeth provide new insight into human ancestor

Australopithecus sediba : Wiki Commons

- Advertisement -

Species identified in 2010 is 1 of closest relatives to humans A dental study of fossilized remains found in South Africa in 2008 provides new support that this species is one of the closest relatives to early humans.

The teeth of this species – called Australopithecus sediba – indicate that it is also a close relative to the previously identified Australopithecus africanus. Both of these species are clearly more closely related to humans than other australopiths from east Africa, according to the new research.

The study, published in the journal Science, revealed that both africanus and sediba shared about the same number of dental traits with the first undeniably human species.

“Our study provides further evidence that sediba is indeed a very close relative of early humans, but we can’t definitively determine its position relative to africanus, said Debbie Guatelli-Steinberg, co-author of the study and professor of anthropology at The Ohio State University.

The research was led by Joel D. Irish, professor of natural sciences at Liverpool John Moores University.

The sediba fossils were found in South Africa in 2008 and first described in a series of articles published in Science in 2010. That study was led by Lee Berger of the University of Witwatersrand in South Africa, who is also a co-author of this new study.

- Advertisement -

In this study, Irish, Guatelli-Steinberg and their colleagues extended that work by examining the teeth from sediba and comparing them to eight other African hominin species, which include modern humans from Africa, and extinct species of Homo, Australopithecus, and Paranthropus. In all, the researchers examined more than 340 fossils and 4,571 recent specimens. They also examined teeth from 44 gorillas for comparison.

The focus was on 22 separate traits of tooth crowns and roots that can give clues as to the relationship between the different species studied.

For example, they measured how much one of the incisors was shovel-shaped. Depending on the species in this study, the incisor may have no depression in the back of the tooth, a faint shovel shape, or a trace of that shape.

Researchers use standardized measurements from the Arizona State University Dental Anthropology System to compare the teeth on these 22 traits.

The researchers found that on 15 of these traits, sediba and africanus scored the same. Sediba shared 13 traits with Homo erectus, an early human species, which was comparable to how africanus scored.

Sediba and africanus shared five dental traits that weren’t found in earlier australopiths, further showing their close relationship. Both also share five traits with early humans – Homo habilis/rudolfenis and Homo erectus — which weren’t shared with earlier ancestors, demonstrating the close relationship between these two australopiths and the first humans.

Teeth are an excellent way to study relationships between different species, Guatelli-Steinberg said. They are well preserved in the fossil record, and researchers can compare large samples, at least for many ancient species.

In addition, most of the dental traits the researchers used in this analysis don’t have a selective advantage that could help one species survive over another. That means if researchers see a similar trait in two species, they can be more confident that they shared a common ancestor and that the trait didn’t evolve independently.

In many ways, these new dental data support the earlier research on sediba, which included analysis of the inside of the skull, hand, spine, pelvis, foot and ankle, Guatelli-Steinberg said.

“All of the research so far shows that sediba had a mosaic of primitive traits and newer traits that suggest it was a bridge between earlier australopiths and the first humans,” she said.

Guatelli-Steinberg said their dental analysis showed that both africanus and sediba are more closely related to humans than the famous “Lucy” skeleton fossil found in East Africa in 1974. This fossil represented a species, Australopithecus afarensis, that was at one time was thought to be the closest relative of humans.

Lucy is estimated to have lived 3.2 million years ago. Sediba lived 1.977 million years ago, while africanus lived between 3.03 and 2.04 million years ago.

“Our research on teeth can’t definitively settle if either sediba or africanus is more closely related to humans than the other species,” Guatelli-Steinberg said. “But our findings do suggest that both are closely related to each other and are more closely related to humans than afarensis.

“We need to find more sediba remains to help fill in the missing pieces of this evolutionary puzzle.”

Contributing Source : Ohio State University

HeritageDaily : Palaeoanthropology News

- Advertisement -
spot_img
Mark Milligan
Mark Milligan
Mark Milligan is multi-award-winning journalist and the Managing Editor at HeritageDaily. His background is in archaeology and computer science, having written over 8,000 articles across several online publications. Mark is a member of the Association of British Science Writers (ABSW), the World Federation of Science Journalists, and in 2023 was the recipient of the British Citizen Award for Education, the BCA Medal of Honour, and the UK Prime Minister's Points of Light Award.
spot_img

Mobile Application

spot_img

Related Articles

Archaeologists uncover votive altar on Mount Arriaundi

Archaeologists from Aranzadi have uncovered a votive altar while excavating the medieval monastery of Doneztebe on Mount Arriaundi, Spain.

Byzantine plaque carved from bone found in Suzdal

Archaeologists from the Institute of Archaeology RAS have discovered a Byzantine plaque, intricately carved from animal bone, within the historic walls of Suzdal, Russia.

Coin hoard from time of the Gallus Revolt unearthed in Lod

Archaeologists from the Israel Antiquities Authority (IAA) and the Lod Municipality have unearthed a hoard of 94 coins in Lod from the time of the Gallus Revolt.

Rare religious treasures uncovered near Lake Tisza

Archaeologists from the National Archaeological Institute have uncovered a rare silver Eucharist set alongside a treasure hoard of silver coins.

Archaeologists may have discovered the lost city of Tu’am

Excavations in the Umm Al Quwain area of the UAE have revealed 6th century ruins that could be the lost city of Tu'am.

New findings in North America’s first city

Cahokia was the largest urban settlement of the Mississippian culture, a mound-building pre-Columbian civilisation that emerged in the Midwestern, Eastern, and South-eastern United States.

Bottled fruit cache discovered at George Washington’s Mount Vernon

Archaeologists have discovered a cache of 35 glass bottles at Mount Vernon, the former residence and plantation of President George Washington.

Mysterious engraving might depict an Archaic temple on the Acropolis of Athens

A 2,000-year-old engraving on a marble outcrop near Vari, Attica, might point to an Archaic temple on the Acropolis of Athens.