Examples of axial symmetry abound, but I could not find an example of pure central symmetry (that is, without axial symmetry)! Do you know of any? A butterfly shows axial symmetry, what shows point/central symmetry in nature?
So, many examples resemble even functions, but I am looking for something that resembles an odd function. The best I can come up with is the image of a wave. But natural waves tend to be complicated and simple waves look too mathy.
Edit and to clarify: The question and terminology were vague. I left it as it was so that the connection to discussions below is not lost. Here is another attempt at explaining the question.
Odd and even functions are brought up early in college algebra. y=x^2 is even and exhibits symmetry with respect to the y-axis. Symmetry with respect to an axis is quite common in nature and one can find many examples. y=x^3 is odd and it exhibits symmetry with respect to the origin, if (x,y) is on the graph so is (-x,-y). I am looking for natural examples of symmetry with respect to origin, without the presence of symmetry with respect to an axis.
Thanks to the answers below I found the following (Figure 1b is what I was looking for) taken from this paper.
If you have other examples please post a picture or give a link.
Trivia: After this post I asked ChatGPT the same question. After two obviously incorrect answers it said it cannot find any!