Remains of obsolete endings in Atlantean nouns

1. The dual case.

This case, formerly present in Juralic, had largely died out in early times, but remains  fossilised  in a few set expressions in Atlantean as well as Yalland. In Atlantean, it originally involved the interpolation of -ET- between the root ending and the suffix. (See the section on Juralic: Historical grammar of Juralic languages,2, pronouns, adjectives and nouns).

Examples are: 
THETTETO, from THETTO (brother), meaning "brother and sister".
NUMETO, from NUMO (eye), meaning " a pair of eyes". (This also survived in Yalland: NOIMOI (eye) and NOIMIDOI (pair of eyes).
THUYETA, from THUYE (wind) meaning the "Divine Winds", ie: winds which were believed to be gods.

2. Plural endings in -AI.

-I: was the original Juralic plural ending, which died out in favour of -IX in Atlantean. Traces of it remain in certain nouns with irregular declensions, eg:

CELEUO (nom song, a noble), CELAI (nom, acc plural)
DAO (nom sing, god), DAI (nom, acc plural)

Also the following irregular adjectives:

CEL (nom sing, noble), CELAI (nom, acc plural)
THIAL (nom sing, this), THIAI (nom, acc plural, these)
THAIR (nom sing, that), THAI (nom, acc plural, those)

We can note also the following fixed meanings for certain nouns and adjectives:

THETTAI (old plural of THETTO, brother), meaning "band of brothers", adopted by the Brotherhood Party in the 790s period.
YCATHAI (library), related to CATHA (book)
IASAI (life), literally plural of IASU (year).

3. The vocative case

The vocative case had been subsumed into the nominative very early on, but a few examples of the vocative singular case survived for declension 1 nouns. These had the ending -A (from Juralic -A:
One example is the vocative singular of DAO (god), which was DA (O god!)

4. The locative case

The true successor of the Juralic locative singular ending -SSE was -S in Atlamtean, but this had been replaced in early Atlantean by -SIL from the preposition SIL, meaning "in".

However, the old ending survived in Classical Atlantean in a few set expressions:

THESAS (from THESEI, house), meaning "at home".
CERTAS (from an obsolete word CER, ruler), meaning "at court", literally "with the ruler".
BUAIMAXANAS , in the past.
LOUANAS, a long time ago.
MARRANAS, recently
BOUNAS, at the mercy (of)