Somebody gave me this last night ...
(Here's the link to the real version … in color, even!)
A lot of American English speakers don't produce an actual 'n' in a word like can't. We instead nasalize the vowel, [kæ̃t], sometimes also with a final glottal stop instead of the 't'. The story is that this happens when the nasal is followed in the same syllable by another consonant, so that you have an 'n' in can but not can't. But in Atlantis, some of us can flap the 't' and so don't have a full nasal here either. (We don't lose the contrast, just the 'n': nasalization on the vowel keeps antic versus attic clear.)
In other words, some of us DO have a lost consonant of Atlantis. Kinda.