|A skull of Romundina, a transitional form |
between jawed and jawless vertebrates
|A 3D x-ray scan of a tooth plate from Romundina. The oldest 'pioneer' tooth is coloured |
gold. The subunits are increasingly younger as you go further out from the centre
The process started with a single central 'pioneer' tooth around which additional tooth-like structures agglomerated, the overall tooth plate steadily growing outwards. Each subunit possessed a distinct core of dentine and an enamel covering much like our own teeth, but had failed to differentiate from the overall tooth plate. In time these subunits did eventually differentiate to form individual teeth capable of their own development. Mammals would take this a step further with each tooth gaining a distinct identity, for example as a flat, textured molar or a pointed canine. Yet this heritage may ultimately lie in the tooth plates of Romundina and its kin.