23-05-2025
Your Teeth May Have Evolved From Ancient Fish Armor
The next time you wince from an ice-cold drink or a too-hot slice of pizza, blame your ancestors. Specifically, the armor-plated fish that swam Earth's oceans over 460 million years ago.
A new study published in Nature traces the evolutionary origin of human teeth to sensory structures found on the exoskeletons of extinct fish. Researchers say the same "genetic toolkit" that creates dentine—the hard, sensitive tissue beneath the enamel in modern teeth—was first used by ancient sea creatures to sense their environment.
'This shows us that 'teeth' can also be sensory even when they're not in the mouth,' said study co-author Yara Haridy, a paleontologist at the University of Chicago.
The breakthrough came when scientists were analyzing fossilized remains of jawless fish like Anatolepis heintzi using high-resolution CT scans. While initially thought to be early vertebrates based on their dentine-like structures, the team found something surprising: sensory pores resembling those in the shells of crabs, not fish.
That reclassification helped clarify something bigger. Both early arthropods and early vertebrates were developing mineralized sensory tissues in their armor. Eventually, those same tissues evolved into something more internal, refined, and, millions of years later, familiar: human CT scans also captured vivid detail in species like Astraspis, revealing dentine-filled tubules and vascular networks, showing how these ancient sensors were wired into the nervous system. The similarities to today's dental structures are striking.
'Viewed through this evolutionary lens, the fact that teeth in the mouth are extremely sensitive is less of a mystery,' the authors wrote. 'It's a reflection of their evolutionary origins within the sensory armor of early vertebrates.'
In short, your teeth are the last echo of a prehistoric defense system designed not to chew, but to Teeth May Have Evolved From Ancient Fish Armor first appeared on Men's Journal on May 22, 2025
