An international research team reports the analysis of new hominin fossils from the site of Thomas Quarry I (Casablanca, Morocco). The fossils are very securely dated to 773,000 +/- 4,000 years ago, thanks to a high-resolution magnetostratigraphic record capturing in detail the Brunhes/Matuyama boundary, the last main geomagnetic polarity reversal and precise temporal markers of the Quaternary.