Machikane Crocodylidae (Toyotamaphimeia Machikanensis) fossil designated as a Natural Monument

The Machikane Crocodylidae (Toyotamaphimeia Machikanensis) fossil housed and displayed at the Museum of Osaka University was designated as a Natural Monument, reported in an official gazette dated September 18,2025. This marks the first such designation in Osaka Prefecture in the last 69 years.

The Machikane Crocodylidae fossil was discovered accidentally in some 420,000-year-old layer of earth in May 1964, during the construction of the School of Science on the Toyonaka campus of the University of Osaka. It is the first complete skeletal fossil of a crocodile discovered in Japan and is one of the most complete skeletal fossils of a crocodile ever found in the country. It is also the motif of our university's official mascot character, "Dr. Wani."

In response to the news that the Machikane Crocodylidae fossil, often referred to as “Treasure of the University of Osaka,” was designated as a natural monument, the Museum of Osaka University will host various events. Please take this opportunity to visit the museum.
◆Permanent Exhibition & Guided Tour
[Date and time] *Approximately 45 minutes *No prior registration required
①October 11 (Sat) 11:00 AM～
②October 18 (Sat) 11:00 AM～, 2:00 PM～
③October 25 (Sat) 11:00 AM～, 2:00 PM～
[Venue] Machikaneyama Shugakukan, The Museum of Osaka University

Our students will provide explanations about the exhibition, as well as the Machikane Crocodylidae fossil. This is a rare opportunity to view the actual Machikane Crocodylidae fossil, which measures approximately 7 meters in length, and listen to detailed explanations. We plan to distribute Dr. Wani stickers as a novelty item to those who wish (ends when the stock runs out).

[Guide] UOsaka students (Assistants at the Museum of Osaka University)
[Participation Fee] Free of charge
[Capacity] The first 30 people to arrive for each session

◆Events related to the Machikane Crocodylidae fossil
(To be held at the booth of the Museum of Osaka University, on the occasion of the University of Osaka Co-Creation Day @EXPOCITY: “Stimulate your five senses and experience the unknown!”)
[Date and time] October 18 (Sat)
[Venue] LaLaport EXPOCITY

This event invites you to explore the Machikane Crocodile through activities like a quiz contest, origami, and Dr. Wani sticker giveaway.

[Participation Fee] Free of charge

◆Other Related Events
Academic symposiums and events targeting children are planned for January 2026 and beyond.

The age of the Machikane Crocodylidae (Toyotamaphimeia Machikanensis) fossil has previously been described as “approximately 450,000 years ago.”
Based on the notice below from the Museum of Osaka University, it has been revised more accurately to “approximately 420,000 years ago.” (Updated on June 4, 2026)

＜Related Link＞
Announcement from the Museum of Osaka University
Revision of the age description of the Machikane Crocodylidae (Toyotamaphimeia Machikanensis) fossil