What is the difference between the mridangam and the tabla?

The mridangam is one double-headed barrel drum, played across the lap with both heads struck by the hands. It is the principal percussion of Carnatic music in South India. A widely held tradition says the tabla of Hindustani music came from a mridangam split in two, but this story is unverified. Its closest Hindustani relative is the larger pakhawaj.