The band Hotlegs was a kind of precursor to 10cc. The trio who recorded this (Eric Stewart, Lol Crème and Kevin Godley) all went on to be in that group as did Graham Gouldman who was a member of Hotlegs but unable to play on this for contractual reasons.

Hotlegs: Neanderthal Man

In looking the above video up I came across this recording of the song for one of those compilation albums of knock-off versions of recent hits. The singer here?

A guy who went on to become Elton John.

Elton John: Neanderthal Man