定義： The number of fossil occurrences in the Paleobiology Database (https://paleobiodb.org) that are identified as belonging to a particular taxon or any of its subtaxa.
定義： This organism produces this material or substance, either during its life or after death. A produces B if some process that occurs in A has output B.
定義： A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)
