Basic researches on morphological analysis of ostracods using pattern recognition by a computer and its application on taxonomy.

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Microstructures of eye tubercles, sensory or secretion pores, hinges, muscle scars, as well as various ornamentations on the carapace, can be used as basic criteria for classification of ostracods because of their functional significance. The purpose of this study is: 1) to clarify the biological significance of these structures; 2) to establish a new classification of ostracods based on the functions of these morphological elements evaluated by pattern recognition of them by a computer; 3) to apply this classification to elucidate the mechanism of speciation of ostracods.This research was carried out in the following sequence.1. LUZEX II (a new computer system) was developed for morphological analysis.2. Preparatory works for morphological analysis was carried out using quartz particles into metamorphic rocks as experimental models.3. The degree of coarseness/fineness of surface reticulation and the number and distribution pattern of the pores were examined ontogenetically using the ostracod genera Cythere and Cytheromorpha.(1). It was found that Cytheromorpha has a wide inner-specific variation in the degree of reticulation, and it is closely related to the water temperature at growing stages.(2). It was also found in Cythere that the number and distribution pattern of the pores are highly stable characters within each species.4. These characters were used as the basis for re-classification of both fossil and Recent species belonging to these genera from all over the world, and the phylogenetic relations among these species were also discussed. Five lineages within genus Cythere were recognized, and the processes of speciation from the Miocene to the present were elucidated. Some of these results have already been published in research papers, and others are being prepared for publication.