In light of the "Komodo dragons have iron deposited in their teeth" study, I want to know WHY sea lion and fur seal teeth are stained brown/red/black. No other pinnipeds have such teeth, nor do other marine mammals or terrestrial carnivores to my knowledge. Somebody [else] needs to study this!

Huh. Good question!

It's a steady diet of licorice.

Newborn pups have white teeth, and the staining happens with age. But, I haven't been able to find any articles explaining the color change.