Movie S2.

Soft-tissue contrast (PTA-stained) microCT scan of the hatchling catshark lower jaw segment. Large taste buds are present at the junction with the emerging teeth at the jaw margins. Skin denticles are also present on the outer surface of the segment.

Sox2+ progenitors in sharks link taste development with the evolution of regenerative teeth from denticles

Kyle J. Martin, Liam J. Rasch, Rory L. Cooper, Brian D. Metscher, Zerina Johanson, and Gareth J. Fraser

PNAS. 2016. 113:14769-14774 DOI: 10.1073/pnas.1612354113