Scientists have made a groundbreaking discovery about the origins of human teeth, revealing that they evolved from the “body armor” of extinct fish over 460 million years ago. The study, published in the journal Nature, shows that sensory tissue discovered on ancient fish exoskeletons is linked to the same genetic toolkit that produces human teeth.
The researchers started by searching for the earliest vertebrate species in the fossil record, focusing on the Cambrian and Ordovician periods. They used high-resolution CT scans to investigate a jawless “first fish” species called Anatolepis heintzi. Initially, they thought the pores found on its exoskeleton were dentine-lined, but further analysis revealed that they were actually sensory organs similar to those on crab shells.
This mistake led to an important new insight: ancient vertebrates and arthropods made the same mineralized tissue to sense their environment, which later evolved into dentine. The study supports the idea that sensory structures evolved at least 460 million years ago and that animals used the same genetic toolkit to make teeth.
The researchers believe that the sensitivity of human teeth is a reflection of their evolutionary origins in the sensory armor of early vertebrates. This new understanding sheds light on how our teeth became sensitive, revealing a fascinating connection between ancient fish and modern humans.
Source: https://www.livescience.com/animals/our-teeth-evolved-from-fish-body-armor-over-460-million-years-scientists-discover