The casing model associated with the New Dalek Paradigm (TV: Victory of the Daleks) sported a back panel which ran down the back of the base unit, linking the weapons platform to the fender. As the Time Lords noted, this back panel contained hardware to extend the Dalek's functional capabilities. (PROSE: Dalek Combat Training Manual) A later modification to this casing type, in use by the Asylum Incident, slimmed down the back panel. (TV: Asylum of the Daleks)
Behind the scenes
- As explained by designer Peter McKinstry, the "spine section" was intended to provide an aperture that could open up and reveal new weapons. (The Dalek Handbook)