Figure 3 in Environmental control versus phylogenic fingerprint in ontogeny: The example of the development of the stalk in the genus Guillecrinus (stalked crinoids, Echinodermata)

Figure 3. Morphological units versus functional units, and symmetries at two levels of integration (ossicle and stalk). (a) A columnal viewed along its proximal/distal axis; (b) symmetry produced by superimposing the proximal and distal fulcral ridges of the columnal in (a); (c) superposition of articular fulcra of all columnals along the stalk; (d) schematic diagram of morphological and functional stalk units and their interactions.