The bottom of Yurdle’s shell is so plain, isn’t that not a good sign?
It’s fine! The bottom of a turtles shell is called a “plastron” and it varies in size, shape, color, and pattern from species to species. Yurdle is an eastern painted turtle, and this species has a being colored plastron. Other members of the genus do have a colorful pattern on their plastron, but not him!
(picture yanked from the wikipedia article on painted turtles!)
FYI my turtle owning friends.