But starfish—as well as sand dollars and sea anemones—have radial symmetry, with identical segments of their body radiating out from a central point.

The end result, constructed at Harvard, resembled the nave of a cathedral built by aliens to worship radial symmetry, or an iron maiden for punishing giant cubes.

Stranger still, this "handedness" is the only feature that breaks the comb jelly's radial symmetry.

If a vertebrate had for some reason adopted radial symmetry, could we have seen equally surprising ways of seeing in our own ranks?

The plan involves bilateral symmetry, rather than radial symmetry; protective sepals alternating with petals; and usually a special lower petal, called a lip, that can serve as a landing pad for pollinators.