Meeting Abstract
While functional morphologists have long studied the evolution of suites of trophic structures, the origin and evolution of morphological novelties has received less attention. One difficulty regarding the incorporation of the origin of anatomical novelties into evolutionary theory is that novelties may originate in piecemeal fashion rendering them more difficult to study. Alternatively, there may be times when complex structures originate all at once. When such complex novelties first originate they must become incorporated into an existing system to be rendered fully functional. Thus, morphological integration is key at the outset of acquisition of morphological novelties. However, given enough evolutionary time such linkages may be broken, allowing for a division of labor that is facilitated by subsequent decoupling of previously integrated structures. Cypriniformes is a diverse group of freshwater fishes characterized by several trophic novelties that include: kinethmoid-mediated premaxillary protrusion, a muscular palatal organ, hypertrophied lower pharyngeal jaws that masticate against the base of the neurocranium, and an epibranchial organ used to aggregate small food particles. Here, we use the wealth of such novelties in different cypriniform fishes to illustrate cases in which trophic novelties require other previously established structures to function appropriately (multistructural functions), such as the co-option of respiratory muscles for the purposes of food aggregation within the epibranchial organ. We will also discuss individual structural novelties that have subsequently become decoupled to take on different functions (multifunctional structures).
