The hypaxial muscle is unusually extended to forward at its upper end and attaches to the neurocranium below the spine, perhaps to snap the upper part of the skull down when catching prey.
Rhomboid muscles | Adductor muscles of the hip | ''Spiral Expansion of Muscles in Action'', plaster, photograph published in 1914 and 1919, in ''Cubists and Post-Impressionism'', by Arthur Jerome Eddy | Epaxial and hypaxial muscles | Color plate by Jacques Gautier d'Agoty, showing some of the muscles of the head. Part of a series of illustrations from Myologie complete en couleur et grandeur naturelle (1746) with texts by French physician and anatomist Guichard Joseph Duverney |