Hobbies And Interests
Skull
The orca skull is asymmetric and "telescoped," meaning that the facial bones are located posteriorly in relation to the brain, according to Digimorph.org. The left nasal orifice is larger than the right, and the blowhole is located more to the left so that the orca may tilt to the right to breathe at the water surface. The facial bones are thicker on the left side, a feature common to all toothed whales.
Spine
The spine has 50 to 52 vertebrae that are linked by intervertebral discs. The vertebrae are similar in size throughout the length of the spine. There are seven cervical vertebrae, the first four of which are fused. The remaining vertebrae are divided into the dorsal vertebrae, lumbosacral, and caudal. There are over 20 caudal vertebrae supporting the large tail.
Ribs and Fins
The orca has 13 pairs of ribs. The two shoulder blades, which help move the pectoral fins, are large and flat. Within the pectoral fin there are short "arm" bones that show a link to land animals that have a humerus, radius and ulna. There is also a "hand" with five carpal and five metacarpal bones, along with five fingers, all of which are fixed and do not move independently.