In 1939 as a 13 year old schoolboy, he discovered early human skeletons and associated artefacts including necklaces, stone tools and moa egg.
The discovery of the ancient Moa-hunter burial sites at Wairau Bar in 1939 provided a new benchmark for archaeologists, ethnologists and anthropologists seeking to understand whose were the first footprints on New Zealand shores.
He was a founder member of the New Zealand Archaeological Association and a council member for two years.
Jim discovered several more burials on the bar, and assisted with the exacavtions carried out by Roger Duff from the Canterbury Museum.