Mid-Cretaceous Biogeography

Global biogeography of Albian ammonoids: A network-based approach

Investigating the spatial structure of the marine biodiversity has long been an important area of biological and palaeontological research.  Biogeographic studies on fossil organisms have contributed to our current understanding of the relationship between plate tectonics, Earth’s climate and the evolution of life. However, the impact of those studies extends beyond basic biogeographic questions to include, for example, conservation biology, regional geology, and stratigraphy. In this study we tested the traditional biogeographic scenario of the Albian Ammonoids using a network-based approach. The results represent the first data–driven delimitation of bioprovinces for the mid-Cretaceous.

Connectivity of the Mid-Cretaceous epicontinental basins:

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The network ilustrated above is a spatially explicit arrangement of 78 nodes connected by 433 weighted edges that covers most of the Albian epicontinental basins and quantifies the strength of the connectivity across most marine regions. This network is fairly sparse (density 0.14), and the number of edges per node approximates a power law distribution (left).