It's likely that the inhabitants of what we in the modern world call Lemuria is a westernization or a Greek reinvention of the original word. The original name is Mu. The spoken language was functionally specific using monosyllabic speech. Their empathic/telepathic communication was instantaneous world wide in higher levels that was separate from the spoken language. The Mäori language of New Zealand is probably a close proximity to the Mu.

As less catastrophic - that's debatable. The Mu Continent sank or was flooded. That sounds catastrophic to me. Some of the Mu left the planet via light beams or spaceships. Many others assimilated into Atlantean culture. This was many thousands of years after the Great Separation.