Overview

• Researchers have traced the evolution of vertebrate teeth to sensory skin structures, known as odontodes, found in jawless fishes around 500 million years ago.
• CT scans of fossils, including Anatolepis, reveal dentin-filled tubuli beneath odontodes, confirming their sensory function and prompting reclassification of some fossils as invertebrates.
• The study highlights how genetic co-option allowed early vertebrates to transform skin sensors into oral teeth as jaws evolved.
• Modern phenomena, such as human tooth sensitivity and the sensory capabilities of narwhal tusks, are linked to this ancient sensory function.
• The findings provide new insights into the evolutionary history of vertebrates and challenge previous assumptions about early vertebrate fossils.