The crested porcupine has characteristic skull morphology with an enlarged nasal cavity, fused shin and calf bones, and reduced collar bone.
The crested porcupine’s skull morphology is characteristic in several ways.
The crested porcupine’s infraorbital foramen is greatly enlarged so that portions of the masseter extend through it and arise from the frontal side surface of the animal’s snout, resulting in a hystricomorphous condition.
The porcupine’s angular process is inflected on the lower jaw and the animal’s nasal cavity is enlarged.
Prominent pocket-like inflations are prominent in the skull, upper jaw, and lacrimal and turbinate bones. The reasons for such pockets are unknown, however they do create enlarged areas of attachment for chewing muscles and could possibly allow the animal to smell underground bulbs during dry periods or wet dry inhaled air.
The crested porcupine’s shin and calf bones are fused and the collar bone is greatly reduced.