We can be certain that Job was a contemporary of Abraham. This means that when Job describes God overturning mountains, he's recounting something that happened recently, about 200 or so years before him.
Abraham and Job
Dinosaurs in Idumea
Depending on which English Bible translation you read, you may or may not see the word dragon occur. Several Hebrew words are translated dragon in the KJV, but are rendered as various other creatures in newer translations.
Dinosaur Classification
Whether or not a Biblical word translated as a kind of serpent refers to something which may have been a dinosaur is context dependent. Sometimes a snake is just a snake. Sometimes a serpent is a Sauropod.
Extinction of Giant Land Reptiles
Behold Behemoth, a Sauropod dinosaur which lived in the Jordan valley during the time of Job and Abraham. Clearly not all of the giant land reptiles were made extinct by Noah's flood.
June 1st
For many years dinosaurs have been classified into two main types based on their hip structure: Ornithischia and Saurischia. Hip structure relates specifically to the different origins of Hydrosphere and Atmosphere.