Figure 2From: The vertebrate taxonomy ontology: a framework for reasoning across model organism and species phenotypesIllustration of the construction of the VTO from source ontologies. AWeb and TTO are grafted (dashed lines) onto the NCBI backbone; PaleoDB taxa are filtered prior to merging with NCBI. AWeb = AmphibiaWeb, NCBI = NCBI taxonomy, PaleoDB = Paleobiology Database (vertebrates only), TTO = Teleost Taxonomic Ontology.Back to article page