Fuchouia from the Cambrian Jialao Formation in Jianhe, Guizhou
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
For a long time, Fuchouia has been regarded as a crucial taxon for biostratigraphic division and correlation of Jialao Formation in Jianhe, Guizhou. However, the systematic positions of Fuchouia and Parafuchouia still remain controversial, with the following three main viewpoints: Parafuchouia is a subgenus of Fuchouia; Parafuchouia is a junior synonym of Fuchouia; and Parafuchouia can be elevated to a separate genus. Based on the specimens of Fuchouia collected from Jialao Formation in Jianhe and previously reported as Parafuchouia or Fuchouia (Parafuchouia), and the specimens of Fuchouia and Parafuchouia previously reported by other authors, we perform statistical analysis on morphological characters of the cranidia of Parafuchouia and Fuchouia using linear measurements. The results indicate that Parafuchouia is a junior synonym of Fuchouia, and its distinguishing features from Fuchouia can be viewed as intraspecific morphological variation. Thus, the Jialao Formation may be the lowest horizon that yields Fuchouia in the world. Although Fuchouia is widely distributed in China, the Democratic People’s Republic of Korea, India-Himalayas, Australia, Kazakhstan and other countries around the world, its occurrences span a wide range of horizons, mostly from the Ptychagnostus atavus Zone of the Drumian Stage to Lejopyge laevigata Zone of the Guzhangian Stage. Hence, it is difficult to use Fuchouia for biostratigraphic correlations. The established Fuchouia biostratigraphic zone of the Cambrian Jialao Formation in Guizhou needs to be further reviewed, and index fossils at the species level or other index fossils need to be selected to make better stratigraphic correlations with the Cambrian slope facies of South China or the Cambrian of North China platform.
