The phrase "ancient supercontinent" refers to a large landmass that existed a long time ago when all continents were joined together as one big land. Full definition
Lambert Graben formed during the breakup of Gondwana, an ancient supercontinent, a process that happened in stages. (scientificamerican.com)
In this case, the location of this magnetic anomaly would then mark the initial location where North America split from the rest of Pangea as that ancient supercontinent broke apart. (sciencedaily.com)
If they can hear, their auditory system must be a survivor of life forms on the ancient supercontinent Gondwana.» (sciencedaily.com)