Scientists have revealed a sophisticated new dating . technique shows that Little Foot, an important fossil of an . early human forerunner unearthed in the 1990s in South Africa, . is roughly 3.7 million years old. 'The age of Little Foot has been highly debated,' said . geologist Darryl Granger of Purdue University in Indiana, whose . research appears in the journal Nature. The study found Little Foot, a member of the species . Australopithecus prometheus, lived at roughly the same time as . Australopithecus afarensis, the species whose most famous . fossil, known as Lucy, comes from Ethiopia. Scroll down for video . The researchers analyzed 11 rock samples from around the nearly complete Little Foot fossil skeleton from theSterkfontein Caves to gauge its age . The researchers analyzed 11 rock samples from around the nearly complete Little Foot fossil skeleton from the Sterkfontein Caves to gauge its age. The species was much bigger and taller than Lucy's, with gorilla-like facial features but fully upright and very strong with powerful hands for climbing. Like Lucy, Little Foot was female. Its hands were proportioned like ours, with a long thumb and . relatively short fingers and palm, unlike the elongated hands of . modern apes. Its legs were slightly longer than its arms, unlike . modern apes. Both species blended ape-like and human-like traits but with different features. The researchers analyzed 11 rock samples from around the . nearly complete Little Foot fossil skeleton from the . Sterkfontein Caves to gauge its age. The findings may have important implications about the . evolutionary relationships among humankind's ancient relatives. Our species, Homo sapiens, appeared roughly 200,000 years . ago. Earlier members of the human genus, Homo, date back more . than 2 million years. Our genus was predated by other species on . the human family tree including various representatives of the . genus Australopithecus. Members of Lucy's species were contemporaries of Little . Foot, although Lucy herself lived about 500,000 years later. Like Lucy, Little Foot was female. The species was much . bigger and taller than Lucy's, with gorilla-like facial features . but fully upright and very strong with powerful hands for . climbing, according to paleoanthropologists Ron Clarke and Kathy . Kuman of the University of the Witwatersrand in Johannesburg. The face of Little Foot, which has now been accurately dated for the first time. Its hands were proportioned like ours, with a long thumb and . relatively short fingers and palm, unlike the elongated hands of . modern apes. Its legs were slightly longer than its arms, unlike . modern apes. Clarke and Kuman noted similarities in facial structure and . some teeth between Little Foot and the later human relative . Paranthropus, indicating Little Foot's species may have been . ancestral to Paranthropus or a close cousin. The new date for Little Foot indicates Lucy's species was . not the only one that could have given rise to later members of . the human family tree, Clarke and Kuman said. 'The fact, therefore, that we have at least two . (Australopithecus) species living at the same time in different . parts of Africa, (about) 3.67 million years ago, raises the . question of how many other species there may have been which . have not yet been discovered,' Clarke and Kuman said by email. The team used Purdue's PRIME Lab's powerful accelerator mass spectrometer and a new detector, called a gas-filled magnet detector, to measure the radioisotopes. 'We succeeded in our measurement, but we were surprised the dates were so old,' said Darryl Granger, a professor of earth, atmospheric and planetary sciences at Purdue. The team used Purdue's PRIME Lab's powerful accelerator mass spectrometer and a new detector, called a gas-filled magnet detector, to measure the radioisotopes. 'We succeeded in our measurement, but we were surprised the dates were so old,' Granger said. 'We double-and triple-checked our results, running the measurement again and again.' The gas-filled magnet creates a different charge on the two radioisotopes and throws the magnesium-26 on a different path with a curvature that misses the detector. This lowers the magnesium ratio and increases the aluminum-26 count in the sample that makes it to the detector, which results in a much smaller margin of error in the measurement. some of the other material found at the site: Stone tools found at a different level of the Sterkfontein cave also were dated at 2.18 million years old, making them among the oldest known stone tools in South Africa. The gas-filled magnet detector was originally to be used to analyze samples of solar wind collected by the Genesis spacecraft. Unfortunately, the space capsule carrying the samples crashed in 2004 on its return to Earth. The crash delayed analysis of the Genesis samples, but Caffee continued to build the detector and it was completed the summer of 2014. Caffee has since used it to perform analysis for other projects, including those from the Sterkfontein site. 'Only a few detectors of this kind exist in the world,' Caffee said. 'We double-and triple-checked our results, running the measurement again and again.' The gas-filled magnet creates a different charge on the two radioisotopes and throws the magnesium-26 on a different path with a curvature that misses the detector. This lowers the magnesium ratio and increases the aluminum-26 count in the sample that makes it to the detector, which results in a much smaller margin of error in the measurement. Ron Clarke, a professor in the Evolutionary Studies Institute at Wits University in South Africa holds the Little Foot skull, among the oldest hominid skeletons ever dated at 3.67 million years old, according to an advanced dating method.  The date places Little Foot as an older relative of Lucy, a famous Australopithecus skeleton dated at 3.2 million years old that was found in Ethiopia. The gas-filled magnet detector was originally to be used to analyze samples of solar wind collected by the Genesis spacecraft. Unfortunately, the space capsule carrying the samples crashed in 2004 on its return to Earth. The crash delayed analysis of the Genesis samples, but Caffee continued to build the detector and it was completed the summer of 2014. The new findings suggest Little Foot roamed the Earth at around the same time as the famed 3.2-million-year-old Lucy, an Australopithecus afarensis - shown in a reconstruction above. When discovered in Hadar, Ethiopia, Lucy was the only skeleton of the species known; she would've stood 3.5 feet (about a meter) tall. Currently, more than 300 individuals of this species, which lived between about 3.85 million and 2.95 million years ago, have been uncovered . Caffee has since used it to perform analysis for other projects, including those from the Sterkfontein site. 'Only a few detectors of this kind exist in the world,' Caffee said. 'One of the reasons I came to Purdue was to be a part of the revolutionary science that can be done when such resources are applied to challenging problems. These results highlight what can be accomplished through a collaboration that spans multiple disciplines. It couldn't have happened without the unique skills and resources each person brought to the table.' INRAP's French researcher Laurent Bruxelles shows Little Foot, a fossil with both ape-like and human features found in a cave at the Sterkfontein site, near Johannesburg. The 'Cradle of Life' is one of eight World Heritage Sites in South Africa . In 2008 the 47,000 hectare site site yielded the . discovery of Australopithecus sediba - thought to be an early human . ancestor that combines simian and modern human characteristics . The world-renowned Sterkfontein Caves is home to the oldest and most continuous paleaontological dig in the world. It is also the site of discovery of the famous pre-human skull affectionately known as 'Mrs Ples', and the almost complete hominid skeleton called 'Little Foot'. Granger's original attempt was the first time aluminum-26 and beryllium-10 radioisotopic dating had been used to determine the age of a fossil. He developed the method in 1997 and first used it to study changes in mountains, rivers and other geological formations. Because of their very slow rate of decay, these particular radioisotopes allow dating to reach back millions of years, much further in history than the more commonly known carbon-14 dating that can only stretch back about 50,000 years, he said. Only a small amount of the radioisotopes remain in the quartz after millions of years, and it can only be measured by the ultrasensitive analysis of accelerator mass spectrometry. 'We had given up and nearly walked away from the project thinking we had failed,' Granger said. 'Then the new detector was completed, and we thought we would give it one last try.' Sorry we are not currently accepting comments on this article.
Little Foot was unearthed in the 1990s in South Africa .
New dating of fossil shows it is is roughly 3.7 million years old .
Lived at roughly the same time as Australopithecus afarensis, the species whose most famous fossil, known as Lucy, comes from Ethiopia .
Raises the question of how many other species there may have been .