Assalmalaikum
Dear Sister in faith and humanity
I am sorry but Quran is not a book of science although Allah has given much scientific details in it. In the case of dinosaurs, there is no human account of there presence and it can only be proved from construction of there bones/fossils.
Even if you beleive in dinosaur or dont beleive in it, it makes no difference as it was past. What we need to really worry about is the future.
Quran [39:55] "And follow the Best of (the courses) revealed to you from your Lord, before the Penalty comes on you - of a sudden while you perceive not!
[Quran 61:10] O you who believe! Shall I lead you to a bargain that will save you from a grievous Penalty?
[Quran 61:11] That you believe in Allah and His Messenger, and that you strive (your utmost) in the Cause of Allah, with your property and your persons: That will be best for you, if you but knew!
[Quran 61:12] He will forgive you your sins, and admit you to Gardens beneath which Rivers flow, and to beautiful mansions in Gardens of Eternity: that is indeed the Supreme Achievement.
[Quran 61:13] And another (favour will He bestow,) which you do love,- help from Allah and a speedy victory. So give the Glad Tidings to the Believers.
hope this answers ur question.