The skulls of most mammals are symmetrical, but there are exceptions,such as odontocete whales. This is part of the normal growth pattern found throughout the taxa. Sea otters
also have been noted to have naturally occurring
asymmetrical skulls, with one side of the skull larger than the
other. A study of a group of sea otters reported the results from
measuring cranial asymmetry in 387 sea otter skulls. Each sea
otter skull was categorized by age: up, juvenile, or adult. The results were as follows.

Question

The skulls of most mammals are symmetrical, but there are exceptions,such as odontocete whales. This is part of the normal growth pattern found throughout the taxa. Sea otters
also have been noted to have naturally occurring
asymmetrical skulls, with one side of the skull larger than the
other. A study of a group of sea otters reported the results from
measuring cranial asymmetry in 387 sea otter skulls. Each sea
otter skull was categorized by age: up, juvenile, or adult. The results were as follows.