Teeth Evolution: How Ancient Fish Scales Transformed Into Human Chompers! | Glass Almanac
Do your teeth have an evolutionary origin of their own, or did they stem from something else? Recent studies lean towards the latter. It appears that the scales of ancient cartilaginous fish migrated toward the mouth following the development of the first jaws. To explore this, researchers at the University of Cambridge employed fluorescent markers to track the cellular development of a cartilaginous fish, Leucoraja erinacea, a type of small skate. Some cartilaginous fishes still retain primitive features that are no longer present in their bony counterparts including small spiny scales embedded in their skin: dermal denticles, which strikingly resemble teeth. The researchers discovered that these spiny scales originate from the same type of cells as teeth: neural crest cells.
“The scales of most modern fish are very different from those of early vertebrates,” says Andrew Gillis from the Department of Zoology at Cambridge and the Marine Biological Laboratory in Woods Hole. “Primitive scales had a structure much more akin to a tooth. These have nevertheless been preserved in some living lineages including those of cartilaginous fish such as rays and sharks. The skin of a shark is entirely covered in dermal denticles,” he continues, “and this explains why this skin has been used as sandpaper since the Bronze Age.”
Source: Teeth Evolution: How Ancient Fish Scales Transformed Into Human Chompers! | Glass Almanac