Why did the Holy Quran not mention extinct animals (such as dinosaurs) or life on Earth before the creation of Adam, even though it is the only reliable historical book for Muslims? And does the lack of their mention mean their non-existence?

The Holy Quran is an eternal miracle for all times and places, encompassing everything people need for their faith and worldly life. It contains many historical and scientific facts, some of which people have discovered, such as its reference to creatures previously unknown, as in Allah’s saying: "And He creates what you do not know" (16:8), and to the existence of ancient civilizations from which lessons can be drawn, as in Allah’s saying: "Have they not traveled through the land and observed how was the end of those before them?" (12:109). The Quran also mentioned tidings whose truths would not become apparent until much later, as in His saying: "For every happening there is a time of settlement, and you will know" (6:67). A Muslim's belief in the Quran does not waver, for everything mentioned therein will become manifest at the times Allah wills.