Which continent did camelids evolve in before spreading to South America and the Old World?

The family Camelidae, which belongs to the order Artiodactyla, first evolved in North America approximately 40 million years ago.1

While the original North American stock eventually became extinct 10,000 years ago, the family spread to other regions over time. During the Pleistocene Epoch, camelids migrated into South America, where they are represented today by animals such as the llama and alpaca. Additionally, by 2 million years ago, representatives of the genus Camelus had crossed into Asia and were present in Africa.1