Columbia, also known as Nuna or Hudsonland, is a hypothetical ancient supercontinent. It was first proposed by John J.W. Rogers and M. Santosh in 2002 and is thought to have existed approximately 2,500 to 1,500 million years ago (Ma), in the Paleoproterozoic era. The assembly of the supercontinent was likely completed during global-scale collisional events from 2,100 to 1,800 Ma
Rodinia (from the Russian родина, rodina, meaning "motherland, birthplace" was a Mesoproterozoic and Neoproterozoic supercontinent that assembled 1.26–0.90 billion years ago (Ga)[5] and broke up 750–633 million years ago (Ma). Valentine & Moores 1970 were probably the first to recognise a Precambrian supercontinent, which they named "Pangaea I." It was renamed "Rodinia" by McMenamin & McMenamin 1990, who also were the first to produce a plate reconstruction and propose a temporal framework for the supercontinent.