Book 32, Question 13
What are the tiny dots on a crocodile’s jaw?
Close up, a crocodile’s jaw has small dark dots.
Each dot is a sense organ that feels the tiniest ripples in water. A crocodile can sense a small splash or movement even in muddy water where it can’t see. Alligators have these dots mostly on their faces, while crocodiles have them all over their bodies. It’s like having extra-sensitive touch.
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Quick answers
What are the tiny dots on a crocodile’s jaw?
The crocodilian sense of touch is concentrated in a series of small, pigmented domes that dot their skin all over their body.
Source: Vanderbilt
More fun facts
- Examining domes on 18 American alligators and 4 Nile crocodiles, he found that the spots contained touch receptors tuned specifically to pressure and vibration, plus a host of raw nerve endings.
- Leitch found that these sensory spots are connected to the brain through the trigeminal ganglia, the nerve bundle that provides sensation to the face and jaw in humans.
- Croc dots, it revealed, could detect ripples from even a single drop of water-and therefore even very weak prey movements.
- Crocodiles and alligators are notorious for their thick skin and well-armored bodies.
- Despite crocodilians' armored bodies, the ISOs imparted a mechanical sensitivity exceeding that of primate fingertips.
Sources: National Geographic, Vanderbilt, National Institutes of Health