Editing Triceps (section)

==Other animals==
In the horse, 84%, 15%, and 3% of the total triceps muscle weight correspond to the long, lateral, and medial heads, respectively.<ref>{{cite journal | vauthors = Watson JC, Wilson AM | title = Muscle architecture of biceps brachii, triceps brachii and supraspinatus in the horse | journal = Journal of Anatomy | volume = 210 | issue = 1 | pages = 32–40 | date = January 2007 | pmid = 17229281 | pmc = 2100266 | doi = 10.1111/j.1469-7580.2006.00669.x }}</ref>

Many mammals, such as dogs, cattle, and pigs, have a fourth head, the accessory head. It lies between the lateral and medial heads.<ref name="Lucas">{{cite journal | vauthors = Lucas-Osma AM, Collazos-Castro JE | title = Compartmentalization in the triceps brachii motoneuron nucleus and its relation to muscle architecture | journal = The Journal of Comparative Neurology | volume = 516 | issue = 3 | pages = 226–39 | date = September 2009 | pmid = 19598170 | doi = 10.1002/cne.22123 | s2cid = 25918513 }}</ref>  In humans, the [[Anconeus muscle|anconeus]] is sometimes loosely called "the fourth head of the triceps brachii".