I suppose if you have never bothered to study the scriptures and being ignorant to the truths revealed therein, you might erroneously think in terms of mythology.
The Hebrew bible mentions the father of Shelah only twice. Once in Genesis 11: 12: "When Arpachshad was 35. he had a son, Shelah.
The only other place where the father of Shelah is mentioned is 1 Chronicles 1: 18; "Arpachshad was the father of Shelah, who was the father of Eber/Heber.
But in Luke 3: 35-36, Luke states that Shelah is the son of Cainam/Kainam, who is the son of Arpachshad.
The book of Jubilees, [Chapter 8]1 In the twenty-ninth jubilee, in the first week, in the beginning thereof Arpachshad took to himself a wife and her name was Rasu’eja, the daughter of Susan, the daughter of Elam, and she 2 bare him a son in the third year in this week, and he called his name Kainam. And the son grew, and his father taught him writing, and he went to seek for himself a place where he might seize for 3 himself a city. And he found a writing which former (generations) had carved on the rock, and he read what was thereon, and he transcribed it and sinned owing to it; for it contained the teaching of the Watchers in accordance with which they used to observe the omens of the sun and moon and 4 stars in all the signs of heaven. And he wrote it down and said nothing regarding it; for he was 5 afraid to speak to Noah about it lest he should be angry with him on account of it. And in the thirtieth jubilee, in the second week, in the first year thereof, he took to himself a wife, and her name was Melka, the daughter of Madai, the son of Japheth, and in the fourth year he begat a son, and 6 called his name Shelah; for he said: ’Truly I have been sent.’