Ben Bacon analysed 20,000-year-old markings on the drawings, concluding they could refer to a lunar calendar.
BBC reports it led to a specialist team proving early Europeans made notes about the timing of animals' reproductive cycles.
Bacon said it was "surreal" to work out for the first time what hunter-gatherers were saying.
Cave paintings of animals such as reindeer, fish and cattle have been found in caves across Europe.
