Paranthropus

The idea was then that it was lithic tool use that was unique to the genus Homo.

Yet again, it was later found that australopithecines utilized lithic tools, and maybe even hominins like Paranthropus, which are not on the Homo lineage.

We know the use of tools was critical to the development of the Homo lineage, and the genus Homo seems to be a lineage that evolved with a reliance on tools, rather than tools being a byproduct of the genus Homo.

The first widely accepted lithic artifacts that appear in the archaeological record are Lomekwian lithics.

Again, we still don't have a very clear idea of the exact hominins that made these tools.

The popular idea is that they were made by early Homo species such as Homo habilis, but it's clear that some of the late-surviving australopithecines had the ability to make and use tools.

And once again, there is some evidence that Paranthropus could use tools as well.

It's possible that all three genera utilized Oldowan tools.

Australopithecines were still around.

Paranthropus, another early human relative with massive jaws for processing tough plant materials, was present.

Multiple species of bipedal apes were living in the same regions at the same time.

It's possible they were all using tools, learning from each other, competing for resources, living in a world much more crowded with human-like intelligence than we usually imagine.