Lethal phase phenotypes. When do they die? - classes for recording and reasoning about the timing of death in lethal phenotypes. - Panel A shows the temporal relationships between Drosophila life stages from the Drosophila stage ontology. The P icon stands for immediately_preceded_by, which corresponds to the Allen relation 'meets’. Panel B shows a set of lethal phenotype terms prior to auto-classification. Panel C shows the same set of classes after auto-classification using the HermiT reasoner.