Evolution of development of vertebrate teeth and scales: unravelling concepts, regulatory theories and homologies
Donoghue, P. C. J.
Paleobiology 28: 474-507 (2002)

Origin and early evolution of vertebrate skeletonization
Donoghue, P. C. J. and Sansom, I. J.
Microscopy Research & Technique 59: 352-372 (2002)