A group of researchers have identified a mollusk that has teeth made of a rare iron mineral called santabarbaraíta (a mineral from the class of phosphate minerals that was discovered in 2000 in the Santa Bárbara mining district of the municipality of Cavriglia, in the Tuscany region (Italy)).
Cryptochiton stelleri is up to 36 centimeters in length and has an oval, shelled body. It is found along the shores of the northern Pacific Ocean from central California to Alaska.
The discovery sheds light on how C. stelleri can scrape food off rocks. Santabarbaraite has a high water content, which makes it strong with low density. This could harden teeth without adding much weight, according to lead study author Derk Joester , an associate professor of materials science and engineering at Northwestern University in Illinois.
To examine a Cryptochiton stelleri tooth, the team used synchrotron spectroscopy and transmission electron microscopy . They found santabarbaraite scattered throughout the upper stiletto of the chiton, a long, hollow structure that connects the head of the tooth to the flexible membrane of the radula.
The new finding helps understand how your entire tooth – not just the ultra-hard and durable cusp – is designed to withstand chewing on rocks for food. Based on the minerals found in teeth, the researchers developed a bio-inspired ink for 3D printing of ultra-hard, rigid and durable materials .