[2] He made his name in the field in July 1955 when at the age of 27 and still working as an amateur, he found the third piece of the oldest human skull in the British Isles while investigating the quarries at Swanscombe in Kent.
He helped redesign the galleries, wrote a description of the Moulsford gold torc and undertook an excavation at the classic Mesolithic site at Thatcham.
To gain wider experience Wymer, at the suggestion of the palaeontologist Louis Leakey, approached Ronald Singer, an anatomist, about working in South Africa.
At Elandsfontein Wymer's excavation of Cutting 10 located a localised grouping dominated by 49 large sharp Acheulian bifaces after Singer had previously found the 'Saldanha Man' skull.
[5] With Ronald Singer, a South African then at the University of Chicago, they exposed a remarkable stratigraphic sequence of more than 20m thick at Klasies River by digging a trench through the site.