5 Answers

My ex-husband was 6’2” so I’m sure he had one of sorts……...

Ducky

:)

More importantly, do they have belly buttons?

I did a search of "worms with backbone" and got this picture....So, guess I don't really know if your statement is true or not. 

THIS IS A SANDCASTLE WORM. IT MADE ITS CASING FROM EGG SHELLS.  IT IS NOT A TAPEWORM, WHICH IS GENERALLY VERY FLAT AND WHITE. A CADDIS FLY CASE WOULDN'T HAVE SHOWN UP IN A SEARCH FOR "WORMS WITH BACKBONES".  THEY ARE AMAZING, THOUGH; CHECK THEM OUT, GOOGLE "CADDIS FLY CASE PHOTOS".
Here's one example:

Only vertebrates have backbones, Worms are annelids so they don't, neither do they have belly buttons so in that respect they are like Adam and Eve, The post by Bob/PBK appears to show a caddis fly case made of grains of sand.

worms are invertebrates they don't have backbones but they have a hydrostatic skeleton