File:Lophosteus superbus tooth replacement.jpg

English: Schematic model of tooth replacement process, starting with the growth of a first-generation tooth (a,b) and passing through the shedding of this tooth (c,d), the growth of a replacement tooth (e,f ), the shedding of this replacement tooth (g,h) and the growth of a second replacement tooth (i,j). Numbers identify the first, second and third tooth. The model aims to explain how the tooth replacement process created the spatial relationships of the resulting resorption surfaces and other structures, but in two important respects it is simplified relative to the actual tooth cushions. Firstly, it does not include a component of lateral displacement. Secondly, it shows the replacement tooth developing after its predecessor has been shed, whereas growth of the replacement tooth in reality probably started alongside the predecessor tooth before shedding.