Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
Beyond doubt the re-introduction of a more delicate and precise pronunciation was connected with the increasing influence of Greek civilization, which is observable at this very period in all departments of Italian life; and, as the silver coins of Capua and Nola are far more perfect than the contemporary asses of Ardea and Rome, writing and language appear also to have been more speedily and fully reduced to rule in the Campanian land than in Latium.
How little, notwithstanding the labour bestowed on it, the Roman language and mode of writing had become settled at the close of this epoch, is shown by the inscriptions preserved from the end of the fifth century, in which the greatest arbitrariness prevails, particularly as to the insertion or omission of -m, -d and -s in final sounds and of -n in the body of a word, and as to the distinguishing of the vowels -o -u and -e -i.(26)
26. In the two epitaphs, of Lucius Scipio consul in 456, and of the consul of the same name in 495, -m and -d are ordinarily wanting in the termination of cases, yet -Luciom- and -Gnaivod- respectively occur once; there occur alongside of one another in the nominative -Cornelio- and -filios-; -cosol-, -cesor-, alongside of -consol-, -censor-; -aidiles-, -dedet-, -ploirume- (= -plurimi-) -hec- (nom. sing.) alongside of -aidilis-, -cepit-, -quei-, -hic-. Rhotacism is already carried out completely; we find -duonoro-(= -bonorum-), -ploirume-, not as in the chant of the Salii -foedesum-, -plusima-. Our surviving inscriptions do not in general precede the age of rhotacism; of the older -s only isolated traces occur, such as afterwards -honos-, -labos- alongside of -honor-, -labor-; and the similar feminine -praenomina-, -Maio- (= -maios- -maior-) and -Mino- in recently found epitaphs at Praeneste.
It is probable that the contemporary Sabellians were in these points further advanced, while the Umbrians were but slightly affected by the regenerating influence of the Greeks.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/2-09-art-science.asp?pg=30