Occam's Razor at work, or, it's Anthropology Day!

Lordkipanidze and colleagues say their work shows the entire early fossil record for Homo – comprising perhaps nine species dating between about 2.3 and 0.5 million years old – is in fact a single long-lived group.
Here’s the list of now apparently defunct species: Homo habilis, Homo rudolfensis, Homo gautengensis, Homo ergaster, Homo georgicus, Homo soloensis, Homo pekinensis and Homo mauritanicus.
All of them would now be sunk into Homo erectus according to the study findings.
Their work also has major implications for later Homo, implying that a further six species should all be sunk into our kind, Homo sapiens. The species no longer required would be: Homo heidelbergensis, Homo rhodesiensis, Homo antecessor, Homo neanderthalensis, Homo helmei and Homo floresiensis.

So, the entire ~2.4 million years of evolution of the genus Homo comprises, this new study proposes, at most two species: Homo erectus and Homo sapiens.