I'm unsure if it's a wiki error or that the item is showing
information inconsistently, but the evolution methods for Clamperl
are the same with different items according to the wiki but on the
evolution pages, one says you can use it on Clamperl but the other
one does not. If this is a wiki error, then both of them are listed
wrong (I doubt it considering the description of the items match
the wiki and the bulbapedia page lists them as a trade holding item
evolution as well), but it seems more likely that there's an error
on the page for DeepSeaTooth's "Use" option since the DeepSeaScale
doesn't have a Pokemon listed as having it be usable on the "Use"
page.
Just remember: You can't prove God didn't crawl out of the
ocean.
(Please give me minor social graces, I have autism and may not
understand what you're saying at first!)