Dinosaurs were created with all the other animals during the first six days. Behemoth and Leviathan, from the book of Job clearly fall into this category of today's dinosaur.
You may hear that Job is a parable, but Ezekiel clearly shows that Job, along with Daniel and Noah, was a true to life man:
Ezekiel 14:
13a:Son of man, when the land sinneth against me by trespassing grievously, then will I stretch out mine hand upon it
14: Though these three men, Noah, Daniel, and Job, were in it, they should deliver but their own souls by their righteousness, saith the Lord GOD.
18a: Though these three men were in it, as I live, saith the Lord GOD
20a: Though Noah, Daniel, and Job, were in it, as I live, saith the Lord GOD
...interesting is that all three men; Job, Daniel, and Noah, all saw dinosaurs with their own eyes:
---NOAH---
Gen 6:18-19 thou shalt come into the ark, thou, and thy sons, and thy wife, and thy sons' wives with thee. And of every living thing of all flesh
---JOB---
Job 40:15a Behold now behemoth, which I made with thee
Job 41:1a Canst thou draw out leviathan with an hook?
---DANIEL---
non-canonical book of Bel and the Dragon 26-27 But give me leave, O king, and I shall slay this dragon without sword or staff. The king said, I give thee leave. Then Daniel took pitch, and fat, and hair, and did seethe them together, and made lumps thereof: this he put in the dragon's mouth, and so the dragon burst in sunder : and Daniel said, Lo, these are the gods ye worship.