The history of Nipponopelta is a case study in the scientific value of keeping specimens available for re-examination. The chronology below follows the university and custodial museum accounts. Dates identify different events rather than competing “discovery dates.”
1995 · Discovery in Yubari
Eijiro Goto found the fossil-bearing concretion in the Yubari area of Hokkaido. The detailed university release identifies Omakizawa, a tributary of the Shuparo River. The material entered Mikasa City Museum, where Hiroshi Hayakawa undertook preparation and research. [Source 2] [Source 3]
1996 · An early scientific report
The university recounts a presentation to the Palaeontological Society of Japan in 1996. At this stage the significance was evidence of nodosaurids in Asia, where their record was sparse. This earlier report should not be cited as the 2026 naming act. [Source 2]
2005 · Detailed description
A paper in the Journal of Vertebrate Paleontology described the material as a nodosaurid. The museum’s retrospective account explains that anatomy still hidden in the rock limited what could be observed. This resource identifies the earlier paper through those primary accounts; it does not claim to have independently reviewed its full text. [Source 2] [Source 3]
Re-examination · CT and comparison
Oyabu revisited the fossil under Kobayashi’s guidance. The museum describes CT scanning as a way to study portions that could not be exposed by further physical rock removal. This added evidence to the anatomical comparison without requiring the same kind of mechanical preparation. [Source 3]
August 21, 2026 · Formal naming
The formal description appeared online in Cretaceous Research. The university’s research team spans Hokkaido University, the University of Calgary, the New Mexico Museum of Natural History and Science, and Mikasa City Museum. Those institutional connections belong to the research, not to this website. [Source 1] [Source 2]
September 2, 2026 · University announcement
Hokkaido University released its public explanation of the findings. It presents Nipponopelta as the first new ankylosaur genus and species named from Japan and the third named non-avian dinosaur from Hokkaido. These are the announcement’s dated descriptions, not a promise that national totals will remain unchanged. [Source 1]
How to use the timeline
When sharing this research, distinguish the field discovery, earlier identification, taxonomic naming and public announcement. Check whether a secondary report has compressed them into a single event. Link the paper and the institutional accounts so readers can see what each date refers to.