Anyone who has ever squirmed through a dental cleaning can tell you how sensitive teeth can be. This sensitivity gives important feedback about temperature, pressure—and yes, pain—as we bite and chew our food. However, the sensitive parts inside the hard enamel first evolved for something quite different.
Holy crap. I’d heard of placoid scales but had no idea they were homologous to teeth. Thank you for sharing.
It’s just a cool piece of information that it’s impossible not to share.