Andon and Fonta had nineteen children and lived to the age of forty-two, when they both were killed in an earthquake. Their first child, Sontad, assumed leadership and this original Andonic clan held together for twenty generations. Andon and Fonta were about thirteen when their first child was born, so assuming Fonta was still having children at the time of her death this gives you some idea of their procreativity.
Meanwhile, to see how truly remarkable Andon and Fonta were, let us step back and look at the big picture.
The first human beings were twins, Andon and Fonta, who founded the human race 993 thousand years ago. Their parents were a different species, called Primates by The Urantia Book, a species decidedly superior to all the primates, the apes and monkeys, we know about. The Primates had perfect thumbs and feet and stood erect, but were not human. Andon and Fonta appeared suddenly, not by any sort of gradual mutation, and were physically superior to and radically different from their parents. Evolution is creativity in time, and this was an eruption of the creativity on tap.