Afossil fish discovered on Pitt Island nearly 30 years ago has finally been fully identified thanks to a surprising source: the field notebooks of the late paleontologist Richard Köhler. The records filled in key gaps about where the specimen was found, allowing researchers to complete a study of what is now considered one of New Zealand’s most remarkable fossil fish.
The find was unearthed in 1999 during a research trip to the Chatham Islands and quickly stood out because of itsunusual state of preservation. Unlike most fish fossils, it retained an impressive three-dimensional shape.
Researchers knew they were dealing with an important specimen, but one missing piece kept the project from moving forward. Without detailed notes on the fossil’s exact location, the team could not formally catalogue it. That changed in 2025 when Köhler’s family donated his notebooks to the University of Otago.
A Discovery That Started With a Ladder
Richard Köhler spotted the fossil in a cliff section above Waihere Bay on the western coast of Pitt Island. Reaching the site was no easy task. The University of Otago reported that after finding the specimen, Köhler walked about three kilometres back to Flowerpot Bay to borrow a ladder. He then returned to the cliff and carefully removed the fossil in several large, heavy blocks before transporting it back to Dunedin.
The fossil immediately caught the attention of scientists.Daphne Lee, Emeritus Professor at the University of Otago, recalled that she and the late Ewan Fordyce were impressed by what Köhler had brought back.
“It was quite unlike any other fish fossil known from Aotearoa New Zealand,” Lee said.
The specimen was later prepared by the late Andrew Grebneff, who helped preserve the details that researchers would eventually study.
Meet a Predator From 55 Million Years Ago
Years later, the find attracted the attention of Mike Gottfried, a fossil fish specialist from Michigan State University. His work helped reveal the identity of the animal. The study, published in the New Zealand Journal of Geology and Geophysics, describes it as a tarpon-like fish measuring about 1.2 metres long. Modern tarpons no longer live in New Zealand waters, but they are known as large predatory fish.
Its long body, strong tail fin, thick scales and upward-facing mouth suggest a similar lifestyle. Researchers described it as a pursuit predator that likely hunted smaller fish. Dating back roughly 55 million years, the specimen represents the first reported Paleogene bony fish of its kind from Aotearoa New Zealand. The new species was named Ikawaihere koehleri.
A Hidden Clue in Family Notebooks
Despite years of work, researchers were unable to finish their study because they lacked detailed information about the fossil’s discovery site.
“However, some key geological information about where the fossil was found was lacking, since Richard had sadly passed away some years earlier,” said the authors.
The breakthrough came unexpectedly in early 2025. One of Köhler’s children, who was studying at the University of Otago, visited the geology department looking for photographs of his father. The visit led to a conversation with Lee and, ultimately, to the donation of Köhler’s field notebooks.
Those notebooks included records from the Pitt Island expedition. Lee said they contained enough information to prepare a Fossil Record Form and officially catalogue the specimen. The completed study was published on 17 January 2026. The species name honors both Richard Köhler and Waihere Bay, where the fossil was discovered. The authors also thanked Heidi Lanauze and the Hokotehi Moriori Trust for approving the name.
“It is a fitting tribute to Richard, Ewan and Andrew. We’re extremely grateful to Richard’s family for donating his notebooks – we could not have done this without them.” Lee said.
Gottfried called the specimen a “remarkable fossil,” saying it expands what scientists know about the evolutionary history of tarpons and preserves unusual features in exceptional detail.