Wastewater Pipe Dig Reveals 'Fossil Treasure Trove'
Published:28 Sep.2023 Source:Taylor & Francis Group
A new New Zealand Journal of Geology and Geophysics paper out today describes the 266 fossil species as one of the richest and most diverse groups of three-million-year-old fauna ever found in New Zealand. At least ten previously unknown species will be described and named in future research.
In 2020, when Auckland's Watercare were excavating two huge vertical shafts for a major upgrade of the major pipeline that brings raw sewage for treatment from the central city they dug through an ancient shell bed. Once they were informed of the fossil deposit's significance, Watercare and their contractors were eager to help and a huge heap of shelly sand was dumped in a nearby paddock so that paleontologists could search through it over many months. As a result, it is estimated that over 300,000 fossils were examined and several thousand have been returned in the museum as a record of this "once-in-a-lifetime find."
It is that the fauna contains fossils that lived in many different environments that have been brought together in the ancient marine channel by wave action and strong tidal currents. It includes ten specimens of the iconic NZ flax snail that must have lived on the adjacent land and been washed down into the sea by storm runoff. These are by far the oldest known flax snails in the world. Most of the fossils lived on the sea floor, some in brackish estuaries, others attached to hard rocky shorelines and still more have been carried in from offshore of the exposed west coast at the time. Rare finds have included isolated baleen whale vertebrae, a broken sperm whale tooth, the spine of an extinct sawshark, dental plates of eagle rays and a number of great white shark teeth.