Ask HN: How were the Baby Bells named?

In 1984 seven Regional Bell Operating Companies were created and spun out of AT&T.

Ameritech, Bell Atlantic, BellSouth, NYNEX, Pacific Telesis, Southwestern Bell, US West

Each of them had a very distinct corporate identity separate from each other and from AT&T, which seems odd given they were generated from the same very stodgy corporate parent with an old and overbearing corporate identity and culture

How did each of the Regional Bell Operating Companies get their names before becoming independent? Was there a concerted effort to have significantly varying names and trademarks? Were the names and trademarks developed after becoming independent from AT&T?