THE DISCOVERY OF THE BATHYNOTUS HOLOPYGUS (HALL, 1859) IN THE CAMBRIAN KAILI FORMATION OF BALANG IN JIANHE, GUIZHOU
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
Bathynotus (Hall, 1859), occurs widely in Laurentia, South China, Australia and Siberia. Bathynotus holopygus (Hall, 1859), one of the representative trilobites of late Cambrian Series 2, has been a dramatic index fossil for the subdivision of the Cam-brian System. The type species of this genus is characterized by its long and slender genal spine, wide axis and a well-developed macropleural spine on 11th segment followed by two distinctly narrow segments; with a narrow geological range and only occurs in South China and North America. The material from South China is mainly found in East Guizhou of the transition zone between the Yangtze Platform and Jiangnan Basin. The vertical extension of B. holopygus-bearing stra-ta is short and only restricted at the top of the Cambrian Stage 4. The appearance of B. holopygus provides an important global stratigraphic marker of the boundary between Cambrian Series 2 and Miaolingian Series. The specimens described in this paper were collected from the layer that is 2 m below the boundary of Wuliuan Stage of Miaolingian Series. This dis-covery is not only the first documentation of this species in the area but also the fourth locality recorded for this species glob-ally. This study deeply describes the characteristics and developmental trends of B. holopygus through the mathematical anal-ysis of its parameters, and provides new materials for the study of this genus. According to the newly discovered specimens, it is inferred that the rostral plate is fused with the hypostome.
