瓶筐类(Calathids)化石几个疑难问题的讨论

根据采自扬子区和新疆塔里木盆地的大量calathids化石的研究,对其硬体构造,生物体定向和生活方式及分类归属问题进行了讨论,并描述了Calathium (Calathella) yangtziensis,Calathium bachuensis,Calathiumelongates 等3个新种。认为此类生物具有多孔的双层体壁,孔道系统与中腔构成清楚的水流循环体系,与海绵类或古杯类类似,应属低级的底栖滤食性动物。在分类学上应与receptaculitids(托盘类)解除隶属关系,不应再将其视为一种托盘藻类,而应归属多孔动物(广义的)门的Soanitidae科。

A DISCUSSION ON SEVERAL PROBLEMS OF CALATHID FOSSILS

Based on the research of numerous Calathid fossils this paper discussed the skeletal structures, growth orientation ,living pattern and taxonomic position of the calathids and described three new species,including Calathium(Calathella)yangtziensis. Calathium bachuensis and Calathium elongates, which were collected from the Yangtze River area and Tarim Basin, Xinjiang, China. The calathids fossil has a pair of porous body wall of which the outer wall is reticulate-patterned and perforated by incurrent pores and canals; while the inner wall has excurrent pores and canals that are rhomboidally arranged meshes. These pores and canals of the organism constitute a system of current circulation through out the central cavity similar to those of sponges or archaeocyathids. The system of current circulation and other characters of skeletal structure in calathids suggest that the organism should be a kind of inferior animal of filter feeder but should not be classified into Receptaculitid algae. For this reason, the Calathids maybe extricated from Receptaculitidae and classified into Soanitidae (Miagkova,1965) of Porifera (in a broad sense) in taxonomy.