An and Ho's dates became widely used, but in 2015, Chinese palaeoanthropologist Zhu-Yu Zhu and colleagues noticed a discontinuity in the stratigraphy, which put the Chenchiawo mandible in Palaeosol Unit 6, and the Gongwangling skull all the way down in Palaeosol Unit 23. This makes them 1.65–1.59 million and 710–684 thousand years old.
An and Ho's dates gained widespread acceptance, but in 2015, Chinese palaeoanthropologist Zhu-Yu Zhu and colleagues identified a discrepancy in the stratigraphy, which placed the Chenchiawo mandible in Palaeosol Unit 6, and the Gongwangling skull as far down in Palaeosol Unit 23. This led to revised age estimates of 1.65–1.59 million and 710–684 thousand years.