How Lost Field Notebooks Cracked a 55-Million-Year-Old Tarpon Fossil

A fossil fish that had been waiting in a museum drawer for nearly a quarter century finally has a name — and the reason it took so long has almost nothing to do with the bones. Researchers at the University of Otago report that a spectacular, three-dimensionally preserved tarpon-like predator from New Zealand could only be formally described once the original collector's long-missing field notebooks turned up. For anyone who collects fossils along South Carolina's blackwater rivers and Eocene quarries, this is a story with a very practical moral buried inside the science.

What Was Found, and Where

The specimen was collected in 1999 by the late Dr. Richard Köhler on Pitt Island in the Chatham Islands, off New Zealand's eastern coast. According to the University of Otago account, Köhler spotted the roughly 1.2-meter fish weathering out of a steep, nearly unreachable cliff face above Waihere Bay. Recovering it meant a three-kilometer hike back to his lodging to borrow a ladder, then hauling the fossil out in several heavy blocks.

What made the find extraordinary was its preservation. Rather than the flattened, pancake-like impressions that most fossil fish become, this one was essentially mummified in three dimensions, retaining its elongated body, thick rigid scales, powerful tail, and a large upward-tilted mouth. Emeritus Professor Daphne Lee and the late Professor Ewan Fordyce recognized immediately that it was unlike any fish fossil previously known from New Zealand.

After careful preparation, the specimen eventually drew the attention of Michigan State University fossil-fish specialist Professor Mike Gottfried. The team identified it as a member of the Megalopidae — the tarpon family — dating to the Paleogene, around 55 million years ago. They named it Ikawaihere koehleri, honoring both Köhler and the discovery site, with the naming approved in consultation with the Hokotehi Moriori Trust. The researchers describe it as the first known top-of-the-food-chain pursuit predator among bony fish from New Zealand's Paleogene rocks, and the study appeared in the New Zealand Journal of Geology and Geophysics.

The Notebooks That Unlocked It

Here is the twist. A draft scientific paper had already been written before Fordyce died in November 2023, but the work stalled. Köhler had passed away years earlier, and with him went the precise geological details of where and how the fossil came out of the cliff. Without that locality information, the team could not file a Fossil Record Form or properly catalogue the specimen scientifically.

The breakthrough came in early 2025 when one of Köhler's children, then studying at Otago, stopped by the department looking for photographs of their father. That visit led the family to donate his field notebooks, including those from the original Pitt Island expedition. Suddenly the researchers had the specific site data they needed, and a decades-old fish finally became a named species. As Lee put it, the completed study is a fitting tribute to the collector, the scientists, and the preparator who all worked on it.

Why This Matters to Lowcountry Collectors

The single biggest takeaway from this story has nothing to do with tarpons and everything to do with documentation. A world-class fossil sat scientifically frozen for years because the data connecting it to a place in the rock record had gone missing. That is not a New Zealand problem — it is the exact issue that quietly diminishes countless finds pulled from South Carolina waterways.

When a diver recovers a whale skull section from a Cooper River ledge, or a collector picks a shark tooth out of a gravel lag on the Edisto, the object without its context loses much of its scientific value. A megalodon tooth is exciting on its own, but a tooth with a recorded river, a described bottom stratum, and a rough depth becomes something a researcher can actually use to reconstruct the reworked Oligocene and Miocene units of the Charleston embayment. If you collect here, a few habits go a long way:

• Note the river or creek, the general stretch, and the setting — ledge, gravel bed, spoil pile, or beach lag.
• Record the date and, where you can, an approximate depth or the layer the piece came from.
• For anything unusual — associated bone, articulated material, a rare taxon — photograph it in place before you move it.
• If a find looks scientifically significant, contact a museum; the SC hobby diver framework exists precisely so meaningful specimens can be reported.

Köhler's notebooks are the analog version of exactly this discipline, and they saved a specimen decades after his death.

The Tarpon Connection Runs Through Our Waters

There is a second, more surprising angle. Tarpon are not some exotic vanished lineage to South Carolina anglers — the Atlantic tarpon, Megalops atlanticus, still runs our coast in the warm months, prowling the sounds and nearshore waters as the same kind of large, fish-swallowing predator its Paleogene relatives apparently were. The New Zealand fossil expands the known evolutionary history of a family whose living members people here recognize on sight.

It is also a useful reminder that bony fish are badly underrepresented in most fossil records compared with sharks. In South Carolina, our Eocene units and the later Oligocene Ashley and Chandler Bridge formations produce enormous quantities of shark teeth because enamel-coated teeth survive burial and reworking beautifully. The delicate skeletons of bony fish rarely do. That is what makes a three-dimensionally preserved fossil tarpon so remarkable, and it hints at how much of the ancient fish community here has simply not survived as fossils. When collectors do find bony-fish material — a vertebra, a jaw fragment, a cluster of scales — it is worth treating as the uncommon prize it is.

The Longer Lesson

Great fossils are found by people willing to hike back for a ladder. But great science depends on the far less glamorous work of writing down where the thing came from. A tarpon that cruised southern-hemisphere seas 55 million years ago got its name because one collector kept careful notes and his family made sure they survived him. Every South Carolina collector holding a field notebook, or a phone with a location pin, is doing the same quiet, essential work.