Figure 3
From: Resilience of marine invertebrate communities during the early Cenozoic hyperthermals
Network analysis of early Cenozoic molluscan communities from the Gulf Coastal Plain. (a,b) Unipartite network graphs showing changes in the composition of molluscan assemblages. Two samples are connected if they share one or more taxa, and each connection weight equals the Bray-Curtis similarity of the samples calculated from taxon data. (a) Bray-Curtis similarity calculated from species data (modularity, 0.399758). (b) Bray-Curtis similarity calculated from genus data (modularity, 0.2434448). In (b), modules found with the walktrap community detection algorithm (step length equal to 5) are illustrated with green and orange connections. (c,d) Bipartite network graphs showing changes in the presence and absence of mollusc taxa among samples. Taxa are connected to their samples, and vice versa, with non-weighted links. The modules found with COPRA method are illustrated with green and orange connections. Black nodes in (c) are species (modularity of sample projection, 0.766; modularity of species projection, 0.795), and in (d) are genera (modularity of sample projection, 0.417; modularity of species projection, 0.551).
