Is “Yu transformed into a bear and the birth of Qi” true?

后世流传大禹治水时化身为熊，涂山氏见之羞惭化为石头，石破而生启。Records in Records of the Grand Historian, Basic Annals of Xia only mention that Yu married a daughter of the Tushan clan and that she bore a son named Qi, without any mention of the supernatural (「夏后帝启，禹之子，其母涂山氏之女也。」source: Basic Annals of Xia.txt). Although there are hints in Songs of Chu, Questions of Heaven, the complete plot of Yu transforming into a bear and the stone splitting to give birth to Qi finds no explicit textual basis in the aforementioned early core classics; it is rather the result of later evolution.