The development of the tooth pattern and dentigerous bones in Polypterus senegalus (Cladistia, Actinopterygii)

摘要: Summary The formation sequence of the tooth-bearing bones and tooth pattern in early ontogeny Polypterus senegalus is investigated using transparent preparation, histological sections, SEM. During attachment step yolk-sac larva first dermal teeth are formed. Teeth appear simultaneously areas maxillary, dentary, dermopalatine, prearticular, coronoid 1 along with separate anlagen these bones. A monostichous arrangement primary established on dermopalatine. Polystichous arrangements do not occur before pterolarval phase, then only connection palate inner dental arcades. Especially pronounced influence structure parasphenoid that becomes much thickened by accretion denticulate platelets, but we found neither evidence for a distinct vomeral contribution to parasphenoid, nor composite origin ectopterygoid ontogeny. First replacement association maxillary dentary as late apterolarval phase. Primary single general type, whereas from phase onward three types can be distinguished restricted certain bearing Relatively ontogeny, dermo-metapterygoid entopterygoid become formed colonised teeth, branchial plates earlier during extrinsic larval feeding. Characteristics development dentition discussed comparison character states other better known fossil recent taxa among Actinopterygii Sarcopterygii. Compared assumed basic actinopterygian fishes, Polypteriformes show derived condition respect structure, arrangement, replacement, differentiation which arises development. This also corresponds observed changes feeding behaviour functional demands life.