The Cambrian witnessed a noteworthy radiation in biodiversity and a remarkable divergence in Bau plans of marine metazoans. Although the temporal and spatial patterns of Cambrian biodiversity have been widely documented, less attention has been paid to the period’s fundamental biogeographic structure and its changes through time. And it remains unclear how these changes scale up to first-order biogeographic patterns, which may provide insights into evolutionary processes during large-scale diversifications at different temporal scales.

Recently, Dr. Na Lin and Dr. Li Qijian from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) and their collaborators from the University of Erlangen-Nuremberg have outlined time-traceable provinces for marine invertebrates across the Cambrian period using a compositional network based on species-level fossil occurrence data. The results have been published online in Paleobiology, the official publication of the Paleontological Society.

The study confirms an increase in regional differences (Fig. 1) in faunal composition and a decrease in by-species geographic distribution during the first three stages. The results also show that general biogeography tends to be reshaped after global extinction pulses (Fig. 2). The authors suggest that the abrupt biogeographic differentiation during the Cambrian radiation was controlled by a combination of tectonics, paleoclimate, and dispersal capacity changes. This study provides further evidence for the evolution of biogeographic patterns during and after the Cambrian radiation.

Fig. 1 Trajectory of provinciality from the Fortunian to Stage 10 of the Cambrian, based on Hurlbert’s probability of interspecific encounter [IMAGE: PIE]

Fig. 2 Paleogeographic positions of sampled bioregions for the ten Cambrian stages. Numbers and colors indicate time-traceable bioregions. [IMAGE: PIE]

It was jointly supported by the Youth Innovation Promotion Association of CAS, grants from the Strategic Priority Research Program (B) of CAS and the State Key Laboratory of Palaeobiology and Stratigraphy (NIGAPS).

Reference: Na, L., Kocsis, á, Li, Q.*, & Kiessling, W. (2022). Coupling of geographic range and provincialism in Cambrian marine invertebrates. Paleobiology, 1-12. https://doi.org/10.1017/pab.2022.36.

For more information, please contact:

Liu Yun (For media)

E-mail: yunliu@nigpas.ac.cn

Nanjing Institute of Geology and Palaeontology,

Chinese Academy of Sciences

Source: Nanjing Institute of Geology and Paleontology,

Chinese Academy of Sciences