Researchers Meave G. Leakey, Fred Spoor, M. Christopher Dean, Craig S. Feibel, Susan C. Antón, Christopher Kiaria, and Louise N. Leakey report for findings about this new research in the evolution of humans in the journal Nature.
Their published findings on August 8, 2012, are reported in the paper "New fossils from Koobi Fora in northern Kenya confirm taxonomic diversity in early Homo" (doi:10.1038/nature11322).
The abstract to their paper states: "The new fossils confirm the presence of two contemporary species of early Homo, in addition to Homo erectus, in the early Pleistocene of eastern Africa."
Homo rudolfensis (Homo = genus, rudolfensis = species) was a hominin with a relatively flat face. It was first identified from a single large skull in 1972. However, it was not clearly identified as a separate species until now.
"This has been problematic: in palaeoanthropology, faces and jaws function like fingerprints for identifying a specimen as a particular species (which is indicated by the second word in a Linnaean title, such as 'rudolfensis'), as opposed to the broader grouping of genus (the first word, as in 'Homo')."
And, "Without complete skulls, it has been difficult to reach a consensus on whether specimens attributed to H. rudolfensis are genuinely members of a distinct species, or actually belong to other Homo species that lived around the same time, such as Homo habilis or Homo erectus."
Further, "Understanding how many different Homo species there were, and whether they lived concurrently, would help to determine whether the history of the human lineage saw fierce competition between multiple hominins, or a steady succession from one species to another."
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