Although clams that lived at the same time as the dinosaurs were a pretty exciting discovery for my sons, other treasure hunters at Kiritehere have found greater riches, including the flat, spiralled shell of the ammonite (a relative of the nautilus) and the bones of a dolphin-like marine reptile (the ichthyosaur).
Of course, even the most enthusiastic dinosaur hunters need a few distractions and, fortunately, there were several other Xs marked on our treasure map, including spooky caves, secret waterfalls and giant fossilised oysters, which made for great little breaks on the return journey.
Our quest for treasure had started at the tiny seaside settlement of Mokau where we rented a bach perched on the cliffs looking down the coast to the snow-clad peak of Mt Taranaki.
At the spot where the Mokau River reached the sea, we spent many happy hours discovering the fossil of a scaphopod mollusc or tusk shell, semi-precious gemstones and geological oddities called concretions.
By the end of the expedition so many gems had been found that the captain complained the ship seemed to be lower in the water than when we had started.
But all the crew declared our adventure a huge success. We returned home with lots of treasure: new knowledge, amazing discoveries and precious memories.
FURTHER INFORMATION
* The Kiwi fossil hunters handbook by J Crampton and M Terezow (Random House, $39.99) is a great resource. As well as maps to help locate the treasure, the book includes photos to help identify your finds and heaps of information.
* There's more helpful information on the GNS Science website.
Accommodation: Try Book-a-bach.