Ur is a half a billion older than Antarctica and was in the early time period of existence. It was the only continent on earth known as the "supercontinent", though it was smaller than Australia it gave us information about how the earth was made. The way geologists know how this super continent was made was because they were looking at the historic underwater volcanic eruptions. This cause made new layers of rock therefore making the layers expand. This factor made these continents move to place, to place for billions and billions of years.
For million another million or billion of year there was four other continents. There were Africa,India, Australia and Antarctica. All of these four continents made up the supercontinent and help build up the earth to. While this continent was forming, the oxygen,water and atmospheric activity was present in those time of the Ur. Still no life of the the one of the continent was present until 3 billion years later which sexual reproduction. It did had some life though the life, it was bacteria not real animals like today.