Figure 2. Representation of developmental stages in TrOn.

This figure, exported from the ontology viewer OntoScope, displays the terms downstream of organism. These terms represent the red flour beetle at a specific developmental stage, which in nature are separated by molting (e.g. larva, pupa, adult). Transition stages, during which dramatic changes of morphology occur (i.e. prepupa and embryo) are included in TrOn to cover all developmental stages but were not linked with morphological structures. The is_a relations connect the terms with its parents (see thin black arrows). The anatomical structures are linked with part_of relations to the life stages (see orange arrows). The larval stages are divided into sub stages (L1–L7), which inherit the part_of relations from the parent term larva. Hence, the morphological structures are defined only once for the larval stage. The color of the center of the nodes represent the subset of the ontology the node belongs to, i.e. generic, concrete or mixed class. The border of the node indicates the developmental stage of the represented term.