Carnotaurus was the first theropod dinosaur discovered with a significant number of fossil skin impressions.
These impressions, found beneath the skeleton's right side, come from different body parts, including the lower jaw, the front of the neck, the shoulder girdle, and the rib cage.
The largest patch of skin corresponds to the anterior part of the tail.
Originally, the right side of the skull also was covered with large patches of skin—this was not recognized when the skull was prepared, and these patches were accidentally destroyed.
Still, the surface texture of much of the right side of the skull is very different from that of the left side, and probably shows some features of the scalation pattern of the head.

The skin was built up of a mosaic of polygonal, non-overlapping scales measuring approximately 5 mm (0.20 in) in diameter.
This mosaic was divided by thin, parallel grooves.
Scalation was similar across different body parts with the exception of the head, which apparently showed a different, irregular pattern of scales.
There is no evidence of feathers.
Uniquely for theropods, there were osteoderms (knob-like skin bones) running along the sides of the neck, back and tail in irregular rows.
Each bump showed a low ridge and measured 4 to 5 cm (1.6 to 2.0 in) in diameter.
They were set 8 to 10 cm (3.1 to 3.9 in) apart from each other and became larger towards the animal's top.
The bumps probably represent clusters of condensed scutes, similar to those seen on the soft frill running along the body midline in hadrosaurid ("duck-billed") dinosaurs.
Stephen Czerkas (1997) suggested that these structures may have protected the animal's sides while fighting members of the same species (conspecifics) and other theropods, arguing that similar structures can be found on the neck of the modern iguana where they provide limited protection in combat.
Carnotaurus was the first theropod dinosaur discovered with a significant number of fossil skin impressions. These impressions, found beneath the skeleton's right side, come from different body parts, including the lower jaw, the front of the neck, the shoulder girdle, and the rib cage. The largest patch of skin corresponds to the anterior part of the tail. Originally, the right side of the skull also was covered with large patches of skin—this was not recognized when the skull was prepared, and these patches were accidentally destroyed. Still, the surface texture of much of the right side of the skull is very different from that of the left side, and probably shows some features of the scalation pattern of the head.
The skin was built up of a mosaic of polygonal, non-overlapping scales measuring approximately 5 mm (0.20 in) in diameter. This mosaic was divided by thin, parallel grooves. Scalation was similar across different body parts with the exception of the head, which apparently showed a different, irregular pattern of scales. There is no evidence of feathers. Uniquely for theropods, there were osteoderms (knob-like skin bones) running along the sides of the neck, back and tail in irregular rows. Each bump showed a low ridge and measured 4 to 5 cm (1.6 to 2.0 in) in diameter. They were set 8 to 10 cm (3.1 to 3.9 in) apart from each other and became larger towards the animal's top. The bumps probably represent clusters of condensed scutes, similar to those seen on the soft frill running along the body midline in hadrosaurid ("duck-billed") dinosaurs. Stephen Czerkas (1997) suggested that these structures may have protected the animal's sides while fighting members of the same species (conspecifics) and other theropods, arguing that similar structures can be found on the neck of the modern iguana where they provide limited protection in combat.
Carnotaurus