Oktober 3, 2023
As a part of Keio Yochisha Elementary School's science curriculum on geological strata, the sixth-year students engage in a fossil-hunting activity in class using rough stones collected in Shiobara, a town in Tochigi Prefecture which is a well-known fossil site. Shiobara used to be a caldera lake, formed some 300,000 years ago through volcanic activity. During the exercise, the elementary students break apart rough stones to search for the fossilized remains of insects and other organisms that lived around the lake back then.
While this activity had always been a part of the class, it recently came to light that when a student from Yochisha Elementary School named Yuta Nishimura found a fossil of a paper wasp ten years ago, it was the first discovery of its kind in Japan's scientific record.
The fossil is quite large, with the body measuring 18mm, and belongs to the wasp family (Vespidae) based on the presence of three submarginal cells on its forewing, the two tibial spurs at the tip of its middle leg, and its folded forewing. Likewise, the fossil was determined to be in the genusPolistesof the subfamily Polistinae based on its first metasomal tergum being shaped like a bell rather than a long tube.
While polistine wasps are extremely diverse and widespread throughout the world, their fossil records are scarce. It was not until Yui Takahashi, an instructor at Keio Yochisha Elementary School, started conducting research on the stored fossil that it was revealed to be the first fossilized paper wasp to ever be recorded in Japan and East Asia as a whole. This incredible discovery was published on April 1, 2023, inPaleontological Research, an international journal put out by the Paleontological Society of Japan. (An early digital version of the article was released in November 2022.)
Comments from Instructor Yui Takahashi:
We discovered a fossil of a paper wasp in the strata of Shiobara, the first ever reported in Japan. The person who found this fossil was actually still in elementary school at the time. It was uncovered during a class where students would look for fossils by breaking open rough stones. The student has now graduated from university, but I have heard that he still remembers when he found it. When I tell this story to my students now, they get all fired up about following in those footsteps and making a new discovery of their own.