From Michael Porter at Clemson University:

Seahorse tails are organized into square prisms surrounded by bony plates that are connected by joints.  Many other creatures, ranging from New World monkeys to rodents, have cylindrical tails.

Researchers wanted to know whether the square-prism shape gives seahorse tails a functional advantage.

To find out, the team created a 3D-printed model that mimicked the square prism of a seahorse tail and a hypothetical version that was cylindrical. Then researchers whacked the models with a rubber mallet and twisted and bent them.

Researchers found that the square prototype was stiffer, stronger and more resilient than the circular one when crushed. The square prototype was about half as able to twist, a restriction that could prevent damage to the seahorse and give it better control when it grabs things.

Both prototypes could bend about 90 degrees, although the cylindrical version was slightly less restricted... (cont'd)