The exact number of vertebrae is unknown due to several gaps in the spine of the "Ceratosaurus nasicornis" holotype. At least 20 vertebrae formed the neck and back in front of the sacrum. In the middle portion of the neck, the (bodies) of the vertebrae were as long as they were tall, while in the front and rear portions of the neck, the centra were shorter than their height. The upwards projecting were comparatively large, and in the dorsal (back) vertebrae, were as tall as the vertebral centra were long. The sacrum, consisting of six fused , was arched upwards, with its vertebral centra strongly reduced in height in its middle portion, as is the case in some other ceratosaurians. The tail comprised around 50 and was about half of the animal's total length; in the holotype, it was estimated at . The tail was deep from top to bottom due to its high neural spines and elongated chevrons, bones located below the vertebral centra. As in other dinosaurs, it counterbalanced the body and contained the massive caudofemoralis muscle, which was responsible for forward thrust during locomotion, pulling the upper thigh backwards when contracted.