part of part of tissue tail fin outer fin tissue Part of the fin consisting of flattened epidermal cells elevated into a keel-like structure. outer fin This class was sourced from an external ontology (amphibian_anatomy). Its definitions, naming conventions and relationships may need to be checked for compatibility with uberon In frogs (Anura) the outer fin tissue is present only in tadpoles and sometimes during the embryogenesis of species without tadpoles. In salamanders and caecilians tail fins can persist into reproductive maturity. UBERON:3010380 tail fin outer tail fin