A research team from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) has discovered a new middle Cambrian (5.04 mya) konservat-lagerstätte in the Zhangxia Formation in Shandong Province, North China, and named it the Linyi Lagerstätte.
The Linyi Lagerstätte provides a new window into the morphological disparity, community structure, and paleogeographic distribution of marine fauna following the Cambrian explosion.
Their findings were published in National Science Review on April 5.
The rapid appearance of major animal groups and complex marine communities during the Cambrian explosion is recorded in large part in Burgess Shale-type (BST) lagerstätten.
Nevertheless, most of the well-known Cambrian lagerstätten are restricted to a few terranes, with most of them occurring in South China or Laurentia (the core of present-day North America).
This striking geographical imbalance is particularly evident in the middle Cambrian, with the major Miaolingian lagerstätten, including the Burgess Shale in British Columbia (western Canada) and five lagerstätten in the Great Basin (western USA), being located predominantly in Laurentia. The large temporospatial discrepancy of distribution of the soft-bodied fossil lagerstätten limits our understanding of the Cambrian explosion of animals on Earth.
The limited known spatial distribution of Cambrian lagerstätten thus underscores the importance of the newly discovered Miaolingian Linyi Lagerstätte.
The new assemblage contains a variety of well-preserved soft-bodied fossils, among which the non-trilobite arthropods, particularly the mollisoniids and radiodonts, are the most important groups. The Linyi Lagerstätte is remarkable for its excellent preservation of arthropod limbs, eyes, and guts, with these well-preserved fossils promising to yield new anatomical data bearing on the early evolution of animals.
"The close similarity in taxonomy between the Linyi Lagerstätte of North China and those of Laurentian lagerstätten suggests that North China may have provided a biogeographic link between East Gondwana and Laurentia," said Prof. ZHAO Fangchen, corresponding author of the study.
North China is now an important region for investigating the early evolution of middle Cambrian animals, and its Miaolingian deposits have great potential for yielding additional exceptional biotas.
Since the discovery of the Chengjiang Biota in 1984, South China has gradually become the principal area for the study of early Cambrian lagerstätte. The discovery of the Linyi Lagerstätte may also open a new chapter in the study of middle Cambrian BST deposits in North China.
