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
During the period when the Indo-Germanic nations which are now separated still formed one stock speaking the same language, they attained a certain stage of culture, and they had a vocabulary corresponding to it. This vocabulary the several nations carried along with them, in its conventionally established use, as a common dowry and a foundation for further structures of their own. In it we find not merely the simplest terms denoting existence, actions, perceptions, such as -sum-, -do-, -pater-, the original echo of the impression which the external world made on the mind of man, but also a number of words indicative of culture (not only as respects their roots, but in a form stamped upon them by custom) which are the common property of the Indo-Germanic family, and which cannot be explained either on the principle of an uniform development in the several languages, or on the supposition of their having subsequently borrowed one from another.
In this way we possess evidence of the development of pastoral life at that remote epoch in the unalterably fixed names of domestic animals; the Sanscrit -gaus- is the Latin -bos-, the Greek --bous--; Sanscrit -avis- is the Latin -ovis-, Greek --ois--; Sanscrit -asvas-, Latin -equus-, Greek --ippos--; Sanscrit -hansas-, Latin -anser-, Greek --chein--; Sanscrit -atis-, Latin -anas-, Greek --neissa--; in like manner -pecus-, -sus-, -porcus-, -taurus-, -canis-, are Sanscrit words. Even at this remote period accordingly the stock, on which from the days of Homer down to our own time the intellectual development of mankind has been dependent, had already advanced beyond the lowest stage of civilization, the hunting and fishing epoch, and had attained at least comparative fixity of abode. On the other hand, we have as yet no certain proofs of the existence of agriculture at this period. Language rather favours the negative view. Of the Latin-Greek names of grain none occurs in Sanscrit with the single exception of --zea--, which philologically represents the Sanscrit -yavas-, but denotes in the Indian barley, in Greek spelt. It must indeed be granted that this diversity in the names of cultivated plants, which so strongly contrasts with the essential agreement in the appellations of domestic animals, does not absolutely preclude the supposition of a common original agriculture.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/1-02-earliest-migrations-italy.asp?pg=11