The Channidae are well represented in the fossil record and known from numerous specimens. They likely originated in the south Himalayan region of the Indian subcontinent (modern-day northern India and eastern Pakistan) at least 50 million years ago (Mya), during the Early Eocene epoch. Two of the earliest known species, Eochanna chorlakkiensis and Anchichanna kuldanensis , have both been found in the Middle Eocene of Pakistan. By 17 Mya, during the Early Miocene, Channidae had spread into western and central Eurasia, and by 8 Mya, during the late Tortonian, they existed throughout Africa and East Asia. As Channidae are adapted to climates of high precipitation with mean temperatures of 20°C (68°F), their migrations into Europe and Asia correspond to the development of the Intertropical Convergence Zone, which increased air humidity, and the intensification of the East Asian monsoon. Both weather patterns emerged due to greater vertical growth of the Alps, Pyrenees, and Himalayas, which affected Eurasian climatic patterns.