Main Page | See live article | Alphabetical index Biramous is a term used for branched arthropod appendages. These are most commonly branched into a gill and leg with a common root at a body segment. Each leg/gill structure will be paired with a second biramous structure on the other side of the body. Biramous appendages are best known from trilobites where all the legs -- both on the head and the thorax -- are parts of biramous structures with a gill branching off above the leg. The converse of biramous is uniramous or -- very rarely -- monoramous. Uniramous structures are unbranched. Uniramous structures are also found in arthropods. Examples of uniramous structures are trilobite antennae and the legs of chelicerates. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.