only, while in some related ceratosaurs the maxilla also contributed to this opening. Between the bony nostril and the orbit (eye opening) was the antorbital fenestra. In Carnotaurus, this opening was higher than long, while it was longer than high in related forms such as Skorpiovenator and Majungasaurus. The antorbital fenestra was bounded by a larger depression, the , which was formed by recessed parts of the maxilla in front and the behind. As in all abelisaurids, this depression was small in Carnotaurus. The lower front corner of the antorbital fossa contained a smaller opening, the , which led into an air-filled cavity within the maxilla. The eye was situated in the upper part of the keyhole-shaped orbit. This upper part was proportionally small and subcircular, and separated from the lower part of the orbit by the forward-projecting . It was slightly rotated forward, probably permitting some degree of binocular vision. The keyhole-like shape of the orbit was possibly related to the marked skull shortening, and is also found in related short-snouted abelisaurids. As in all abelisaurids, the (on the skull roof between the eyes) was excluded from the orbit. Behind the orbit were two openings, the on the side and the on the top of the skull. The infratemporal fenestra was tall, short, and kidney-shaped, while the supratemporal fenestra was short and square-shaped. Another opening, the , was located in the lower jaw – in Carnotaurus, this opening was comparatively large. On each side of the upper jaws there were four premaxillary and twelve maxillary teeth, while the lower jaws were equipped with fifteen dentary teeth per side. The teeth had been described as being long and slender, as opposed to the very short teeth seen in other abelisaurids. However, Cerroni and colleagues, in their 2020 description of the skull, stated that all erupted teeth have been severely damaged during excavation and were later reconstructed with plaster (Bonaparte, in 1990, only noted that some lower jaw teeth had been fragmented). Reliable information on the shape of the teeth is therefore limited to replacement teeth and tooth roots that are still enclosed by the jaw, and can be studied using CT imaging. The replacement teeth had low, flattened crowns, were closely spaced, and inclined forwards at approximately 45°. In his 1990 description, Bonaparte noted that the lower jaw was shallow and weakly constructed, with the (the foremost jaw bone) connected