Ribbon worms is a group of animals. There are 1351 species of ribbon worms, in 315 genera and 43 families. This group has been around since the Tithonian Age.
Definition: 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.
Definition: An interaction relationship involving a predation process, where the subject kills the target in order to eat it or to feed to siblings, offspring or group members
Definition: 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)
