碩士 / 國立成功大學 / 地球科學系碩博士班 / 91 / Lots of small clypeasteroid echinoid fossils were collected around Kuantseling area, Tainan. Morphologically they are similar to Taiwanaster mai clypeasteroid echinoid. Comparison between these two kinds of echinoids has been done according to their exterior features and their morphological measurements. Results show that there are certain differences in their exterior features as well as in their morphology. The name of Taiwanaster sp. is therefore given to the fossils. According to difference of morphological features and their occurring geological time point, this paper suggests that Taiwanaster sp. is developed between Taiwanaster pitouensis and Taiwanaster mai in the evolutionary lineage of Taiwanaster.
The main difference between Taiwanaster sp. and Taiwanaster mai are: (1) The continuity of interambulacral plates at oral surface. (2) Distribution of inner structures support. (3) The morphological measurements show that the width to the length is relative in anisometric growth trend in Taiwanaster mai but isometric in Taiwanaster sp..
Two similar trends are also found, according to the morphological measurments in fossil Taiwanaster sp. and living Taiwanaster mai. The ratio of height to length decreases in percentage, however the location of mouth keeps in a constant. It is suggested that these two conclusions may become the classification characteristics of genus Taiwanaster.
| Identifer | oai:union.ndltd.org:TW/091NCKU5135004 |
| Date | January 2003 |
| Creators | Wei-Chia Chu, 朱偉嘉 |
| Contributors | Kuang-Jyi Chung, Ming-Chee Wu, 鍾廣吉, 吳銘志 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 59 |
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