Morphology and Life Habit of Halobia from the Upper Triassic of Western Sichuan
详细信息
- 责任者：Pang Yanchun (Institute of Sedimentary Geology ; Chengdu University of Technology ; Chengdu 610059 ; China) ; Luo Yong
- 刊名：Acta Palaeontologica Sinica
- 出版年：2012
- 卷期：51(3)
- 关键词：海燕蛤 ; Halobia ; 四川 ; Sichuan Province
- 页码：p.320-327
- 图表：3 illus., 1 plate, 1 table, 21 refs.
- 分类号：1102
- issnNo：ISSN0001-6616
- isbnNo：CN32-1188/Q
摘要
A bivalve fossil assemblage is described from the Nalenghai section of the Changtai area in western Sichuan. In this assemblage Halobia yunnanensis and Hpluriradiata are its dominant species. They are preserved mainly in black calcareous shale and well bedded silty slate,which usually formed at the bottom of a shallow or deep sea.As in most Halobia the larval shells have well developed concentric ornamentations,and the boundary between the larval shell and post-larval shell is very clear.Larval shell morphology indicates a planktotrophic early developmental strategy. After infancy,however,the shells of Halobia are thin and flat with a narrow body,the shapes of which may be horizontal or vertically oval or fan-shaped,with concentric ornamentation and/or radiating decoration. Most of the shells have well developed anterior auricles and byssal tubes and posterior triangular sectors. Such varieties of shape and ornamentation suggest that the Halobia had a strong ability to adapt to varied environments. It may have been sessile benthic if the living conditions were good at the bottom of the sea,or probably it would wander away from the benthos,swimming or even pseudofloating in its search for food.