Overview
Both expert knowledge but also as derived from fossil observations? e.g., gut content as well as signs of predation/feeding. Dunne et al. (2008) is probably the quintessential paleo example but there are others…
Methods
References
Dunne, Jennifer A, Richard J Williams, Neo D Martinez, Rachel A Wood, and Douglas H Erwin. 2008. “Compilation and Network Analyses of Cambrian Food Webs.” Edited by Andrew P Dobson. PLoS Biology 6 (4): e102. https://doi.org/10.1371/journal.pbio.0060102.