“We were mapping outcropping sediments in the Upper Mohaka river tributaries, observing for the first time, what might be there. Nobody had really mapped that steep isolated terrain before. We were keen to find what was present between the greywacke basement rocks and the overlapping Upper Tertiary sandstone section. Perhaps nothing – we just didn’t know – maybe the Upper Tertiary rested directly on basement. Was there any Cretaceous section exposed? This was so important to the assessment of the hydrocarbon prospectivity of the region.”
“It was high summer, February 1958 I think, and we were scrambling up this really difficult stream bed, huge boulders, and totally bush covered. We recognised we were stepping on boulders and outcrops of massive concretionary sandstones which we had not seen before. These appeared to be of marine origin, and had fine shell debris in them which was triggering off alert signals to me – There might be other important fossils here! We should look carefully! I was with field assistant Ken Fink Jensen to whom I owe much for his support and encouragement in those days, Together we began to examine some odd protuberances on the surface of certain boulders, which I quickly recognised, because of their shape and texture, had to be organic and which were almost certainly bone remains from some marine creature. I think my initial reaction was that they were fish remains. The rock was hard, very hard, and we extracted several and brought them back to Gisborne.“
“This region became the hunting ground of Mrs Joan Wiffen who followed up our fossil discovery, with many years of hard work there, excavating numerous other finds from the same stream bed. She, with her husband and family team, found many new fossils, some really exciting, including some terrestrial dinosaur remains which must have been washed into those early primeval seas. It has now become one of the most prolific fossil sites in New Zealand.”
The final image shows a mosasaur skull that was found by Joan and her team and is now kept at GNS Science in Lower Hutt.