Placoderms armored fishes, the first jaw animals that lived about 420 million years ago, had real teeth, say biologists, whose article was published in the journal Nature.
Placoderms were the first vertebrates with jaws, which arose out of their bones that support the gills.
Previously, scientists already knew that the jaws of these fish are dotted with numerous outgrowths similar to teeth, but up to the present time, biologists could not answer the question of whether the data is part of the outgrowths of bone or still are real teeth in the modern sense.
In its work, the scientists used X-ray microscopic imaging that allowed them to look inside the rare examples of armored fishes and not destroy it. After that was built 3D-model of the object, and it turned out that placoderms had the real teeth, they have had root canal and dentin.
However, it should be noted that the teeth are not found roots, and they grew almost on the surface of the jaw.
According to scientists, because of this feature they could not recover from the destruction.