A groundbreaking study reveals that teeth initially evolved for sensing the environment rather than biting. This discovery provides new insights into evolutionary biology by tracing the origins of teeth to sensory organs in ancient fish.
Published in Nature, the research demonstrates that dentin, the sensitive tissue beneath enamel, originated as a sensory organ in the exoskeletons of ancient fish. This occurred long before teeth were used for dietary purposes. According to Dr. Yara Haridy and Professor Neil Shubin, dentin acted as a detection system, helping early vertebrates perceive changes in the water, detect threats, and navigate hostile environments approximately 485 to 540 million years ago during the Cambrian period.
By scanning hundreds of Cambrian period fossils, including Eriptychius, using high-resolution computed tomography, researchers found dentin-containing structures in the body armor, not the mouth. This confirms that early teeth served as sensors integrated into the exoskeleton. This discovery highlights how evolution adapts existing structures for new functions, rewriting the history of teeth and reinforcing the idea that today's teeth evolved from sensors on the skin of ancient fish. Understanding these sensory origins provides valuable insights into the evolutionary processes that shaped vertebrates and their interaction with their environment.