Early human fossils older than previously believed
According to a new study due to published in the Journal of Human Evolution, a group of fossils belonging to early humans that were discovered at Koobi Fora in the Turkana Basin of East Africa have been found to be older than previously estimated. The fossils are significant because they provide important pieces to the puzzle of human evolution, in particular the emergence of hominids in East Africa.
An international multi-disciplinary team of scientists used new methods of dating (magnetostratigraphy and strontium isotope stratigraphy) to re-examine the age range for fifteen hominin fossils that were found in the Koobi For a region. The new dating revealed more precise age ranges for the fossils and dates which were older than previously believed. One fossil, for example, had been classified as belonging to the early human species Homo rudolfensis and considered a possible contender for being ancestral to the human line. It had been estimated to be roughly 1.9 million years old. However, the new test revealed a precise age-range constraint between 1.95 and 2.1 million years.
"To address questions regarding the evolutionary origin, radiation and dispersal of the genus Homo, it is crucial to be able to place the occurrence of hominin fossils in a high-resolution chronological framework,” the study authors wrote. “The period around 2 Ma (millions of years ago) in eastern Africa is of particular interest as it is at this time that a more substantial fossil record of the genus Homo is first found."
The Turkana Basin has earned its place as the world’s most important repository of evidence of human origins largely through four decades of exploration through the Koobi Fora Research Project (KFRP). Some 20,000 fossil specimens have been collected from the Turkana Basin, almost 16,000 from the Koobi Fora region alone. The hominid fossil collection, which currently comprises more than 430 specimens, establishes Kenya as a key contributor to human evolution studies. This huge and growing collection of fossils provides an opportunity to trace the evolution of numerous mammalian lineages back in time, including our own.