A few morphological features of interest in development of the nasal apparatus of the magpie (Pica pica L.) . Morphogenesis and evolutionary morphology of the nasal capsule, the nasal epithelial tube and the organ of Jacobson in sauropsida. XVII
Slabý, O.
Folia Morphologica 34(1): 26-35
1986
ISSN/ISBN: 0015-5640 PMID: 3699635 Document Number: 267626
A study of the morphogenesis of three developmental stages of the nasal apparatus of the magpie (Pica pica L.) furnished several morphological findings of comparative and evolutionary interest. Marked reinforcement of the nasal apparatus occurred, manifested in pronounced expansion of some of the cartilaginous elements. For instance, the atrioturbinal spread considerably (together with the vestibule); its large rostral process formed a secondary floor of the nasal cavity and it was supplemented in the rostral region by conspicuous ventral septal processes corresponding to part of the inferior alar cartilage. The question of whether the floor is the true floor of the nasal cavity is discussed. Reinforcement took the form of a cartilage process resembling an accessory maxilloturbinal, buttressing the foramen for the r. medialis nasi. The large orbitonasal lamina participated in the construction of the concha. The spirally constructed complexes vestibule + atrioturbinal and aulax + + maxilloturbinal were remarkably similar to each other and in this case the trend of evolution seems to be towards a kind of meristic organization of turbinals. A comparison of these conclusions with the results of previous studies on the morphogenesis of the nasal apparatus of birds shows that, despite all its specialization, the avian nasal apparatus is capable of further adaptations, that these adaptations develop from "primitive" structures, which are sometimes not even recapitulated (i.e. by a kind of activation of a structure already present), and that, as more and more species are studied, they can furnish information on the trend of evolution.