seems quite plausible, also in the light of (disclaimer: this is not coming from an anthropologist) a notion that the performance of 300 000 year old spares were to rival that of today's high-performance carbon spears (translated in meaning). The latter appears to be quite irritating and would fit the argument of the bipedal suggestion from the linked Nautilus article.

The 300k years coming from the newspaper article below:

Filser, Hubert, 300 000 Jahre alte Speere können mit modernem Olympia-Gerät mithalten (newspaper article) http://www.sueddeutsche.de/wissen/archaeologie-jahre-alte-sp...

which in turn seems to refer to:

Conard et al., Excavations at Schöningen and paradigm shifts in human evolution and Schoch et al., New insights on the wooden weapons from the Paleolithic site of Schoeningen