I guess it is my turn to be that guy.
None of those graphs should be line graphs. There is no continuous X variable.
None of those graphs should be line graphs. There is no continuous X variable.
They also make it easy to visually compare different wear patterns for different species, especially as the teeth are sorted back-to-front. For instance, on the mandible chart, the lines make it very easy to see that the teal, red, and blue lines have similar patterns.
Could you explain why a line graph is bad for a discrete but ordered variable, like [Molars - Premolars - Canines - Incisors]?