JOE DAWSON A piece of dinosaur vertebrae found in a stream west of Mohaka in 1999 has finally been confirmed to have come from one of the largest dinosaurs ever to roam the earth. The bone was found by Havelock North fossil hunter Joan Wiffen, and has now been identified, aftera lengthy research and peer review process, as that of the giant plant-eating sauropod group known as the Titanosauroidea. GNS science said it was the first evidence titanosaurids once lived in New Zealand. Dr Wiffen, in her 80s, said she found the bone on a routine fossil hunting trip in a tributary of the Te Hoe River. "I saw a partly exposed concretion (sedimentary rock) about the size of a rugby ball in the stream bank," she said. "I dug it out and asked a colleague to break it open with a hammer. "I immediately saw a bone structure inside that looked different from the bone of a marine reptile. "To be honest it's a fairly non-descript and incomplete bone. It is heavily eroded and that's because it must have been transported in a riverbed for some time before it was buried." Back at her garage, Dr Wiffen painstakingly removed surplus rock and sediment with acetic acid and abrasion tools. She took the bone to recognised dinosaur expert Dr Ralph Molnar at the Queensland Museum. "Straight away he became quite interested and he thought it might be a tail bone from a titanosaurid." The bone was examined by other vertebrae paleontologists who confirmed the opinion. Dr Wiffen has been a fossil collector for 40 years and she and her team have discovered fossil bones and bone fragments from six dinosaur species that lived in New Zealand, three meat-eaters and three herbivores. They have also discovered fossils of marine reptiles, notably mosasaurs and plesiosaurs, and the flying reptile pterosaurs. "It's all quite exciting because, although we identified dinosaurs first in 1980, there's still a lot to learn. "This one is interesting because it's the first record of that type in New Zealand." Dr Wiffen said she was still as active a fossil hunter as she could be. "But I'm getting a bit ancient for fossicking."
