Results of phylogenetic research indicate that Crocodylus evolved in the Oligocene Indo-Pacific about 25. 5–19. 3 million years ago. The warm and wet climate in the tropics during this period may have facilitated the dispersal of crocodiles from Australasia to Africa without having to move long distances at sea. The genetic lineage comprising saltwater, Nile and Siamese crocodiles is estimated to have diverged 10. 60–6. 52 million years ago. Nile and Siamese crocodiles probably diverged from this group 7. 94–4. 19 million years ago.