Fig. 9 in New hybondontoid shark from the Permocarboniferous (Gzhelian-Asselian) of Guardia Pisano (Sardinia, Italy)

Fig. 9. Hypothetical food chain for the Early Permian Guardia Pisano lake environment based on indirect evidence (dashed lines) derived from functional−morphological interpretations (following Boy and Schindler 2000 and Kriwet et al. 2007). The producers are presupposed for the existence of the 1st (gastropods, ostracods) and 2nd consumers (undetermined branchiosaur, Acanthodes sp., and Lissodus sardiniensis sp. nov.), the 3rd consumer are xenacanthid sharks (Xenacanthus sp.,?Bohemiacanthus sp.), and a diplodoselachid−like shark forms the top predator.