What Are the Differences Between a Cat & a Human Skull?

According to Cold Spring Harbor Laboratory's collective genome research, humans and cats share 90 percent of their genetic code. While 10 percent might seem like a small difference, that percentage is responsible for every physiological distinction between humans and cats. While human skulls serve similar functions in protecting brains and eyes, there are also several distinct differences.

  1. Brain cavity

    • The size of the brain cavity dictates intelligence.

      The hollow chamber inside the cranium is called the brain cavity. The bigger the brain cavity, the bigger the brain. According to Bryn Mawr College's figures, the average size of a human brain is 15 cm in length, and weighs about 1400 g. For a domestic cat, the average length is about 5 cm and the average weight is only 30 g. The size of an animal's brain indicates its capacity for intelligence, so it's no surprise that humans are ahead of the competition here.

    Mandible

    • The mandible of a human skull

      The mandible of the skull is also called the lower jaw. Cats are designed for a habitual carnivorous diet, and their mandibles are suited to this task. Provet, a site for animal health matters, indicates that cats have a dental makeup of three incisors, two canines, three premolars and one pair of molars. This makeup is the same for both upper and lower teeth sets, bringing the total tooth count to 30. Cats have no grinding surface on any of their teeth. They are all sharp and designed for tearing into meat.

      Humans, on the other hand, possess a mandible set designed for omnivorous consumption. Hence, human canines are sharp, with incisors designed to tear, and both molars and premolars bear a flat design for grinding. Provet Health Association states that human dental makeup is two incisors, one pair of canines, two pairs of premolars and three sets of molars for a total of 32 teeth.

    Spinal alignment

    • Human spinal alignment is optimized for bipedal movement.

      Cats walk on all four legs, making them quadrupeds. Therefore, their skulls are balanced in a way to prevent unnecessary stress to the spine. See "Pictures of Cats: Cat Skeleton" for an accurate diagram of a cat's skeleton. The spine attaches further to the back of the skull and at an angle. A cat skull is lightweight, so this sort of alignment maximizes efficiency of their movement and design.

      Humans, on the other hand, are bi-pedal creatures, spending the majority of time walking upright on two feet. The balance of human skulls must be different because of the alignment of the spine and the weight of the skull and its contents. Refer to "Anatomy of the Human Spine" to view a diagram of a typical human skull and spine alignment. The spine connects to the skull in a more central location, to better balance the additional bulk humans possess at the back of the skull.