Creepy catacombs

Jewish catacomb in Rome

I was suprised to read that new research shows that the Jewish catecombs in Rome were older than the Christian catacombs in the city (showing perhaps that the Christians got the idea from the Jews rather than the other way round) -- suprised mostly because I had no idea that there were Jewish catacombs in Rome at all.
Apparently, they were discovered in 1961-62. The best source I've found is this site, which explains,

The Jewish community in the Roman Diaspora dates back to the second century BCE and was comparatively large. Several synagogues and catacombs are known. After the destruction of Jerusalem in 70 CE, the community remained at some distance from the new, rabbinical Judaism of Judaeae, maintaining several archaic traits......
Three factors seem to have influenced the idea to bury people underground. In the first place, the Jews believed in resurrection, a belief that made it impossible to cremate bodies. Secondly, the use of catacombs was a lot cheaper than the purchase of ground for individual burials (which, by the way, are not unknown). In the last place, in Judaea, people were sometimes buried in artificial caves (e.g., at Qumran)...
Most of the 534 names on the inscriptions [in the Jewish catacombs] are Greek: 405 (76%). 123 people (23%) had a Latin name, whereas the remaining 5 inscriptions show Hebrew, Aramaean and hybrid names. This confirms that most Roman Jews were culturally Greek, not Latins...
The use of the Greek language is interesting too. It is grammatically correct, but contains remarkable spelling mistakes.... This suggests that most literate Jews were unable to pay for further education; it more or less corroborates the statement of Juvenal (above) that the Jews were poor...
One inscription mentions a benefactor who married his sister-in-law after his brother had died, a practice that had become obsolete in mainstream Judaism.)... Although one inscription mentions a 'teacher of the Law' the 'new' title of rabbi or Greek/Latin equivalents are not attested in the catacomb inscriptions...
In conclusion, we may probably state that in the first centuries CE, the Jewish community of Rome still retained several traits from a Jewish faith that antedated rabbinical Judaism: no rabbis (at least not in the age of the catacombs)... the custom to marry a sister-in-law still existed.

The Jewish Encyclopedia adds:

The oldest inscription met with in the catacombs is of the second pre-Christian century. Besides individual tombs there were family vaults, and the great age of these may be surmised from the family names which appear on them, as Julii, Claudii, Flavii. To a certain extent the inscriptions reveal the callings which the Jews pursued. The greater part were engaged in business; several were money-brokers; the handicrafts were well represented, and there appear to have been many artists and mechanics among them. There were also Jewish actors, of whom Antyros, during the reign of Nero, and Faustina, in the time of Marcus Aurelius, are known, as well as several contemporaries of Martial.

There is also a vast complex of catacombs at Beth She'arim: See the official MFA site for this.