MAA FOUND MATH: Ammonites are prehistoric squid-like molluscs with spiral-shaped shells, which became extinct about 65 million years ago. The spiral boundary between chambers resembles that of the chambered nautilus, a logarithmic spiral, but not all experts agree. This specimen resides in the Altamirano-Pedrorena House in the Old Town San Diego State Historic Park, and was spotted during the 2013 Joint Mathematics Meetings in San Diego. Photo by Roger Nelsen,Lewis & Clark College.
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