We have animals mentioned in the Bible which sound remarkably like dinosaurs, so they were probably around after the flood, when the Bible was written. Look at some of the descriptions, one of which you mentioned.

Job 40     ¹⁵ “Look now at the behemoth, which I made along with you; he eats grass like an ox. ¹⁶ See now, his strength is in his hips, and his power is in his stomach muscles.
¹⁷ He moves his tail like a cedar; the sinews of his thighs are tightly knit.
¹⁸ His bones are like beams of bronze, his ribs like bars of iron.”

Job 41     ¹ “Can you draw out Leviathan with a hook, or snare his tongue with a line which you lower? ² Can you put a reed through his nose, or pierce his jaw with a hook?
³ Will he make many supplications to you? Will he speak softly to you?
⁴ Will he make a covenant with you? Will you take him as a servant forever?
⁵ Will you play with him as with a bird, or will you leash him for your maidens?
⁶ Will your companions make a banquet of him? Will they apportion him among the merchants? ⁷ Can you fill his skin with harpoons, or his head with fishing spears?
⁸ Lay your hand on him; remember the battle—never do it again!
⁹ Indeed, any hope of overcoming him is false; shall one not be overwhelmed at the sight of him? ¹⁰ No one is so fierce that he would dare stir him up… 

¹² I will not conceal his limbs, his mighty power, or his graceful proportions.
¹³ Who can remove his outer coat? Who can approach him with a double bridle?
¹⁴ Who can open the doors of his face, with his terrible teeth all around?
¹⁵ His rows of scales are his pride, shut up tightly as with a seal;
¹⁶ One is so near another that no air can come between them;
¹⁷ They are joined one to another, they stick together and cannot be parted.
¹⁸ His sneezings flash forth light, and his eyes are like the eyelids of the morning.
¹⁹ Out of his mouth go burning lights; sparks of fire shoot out.
²⁰ Smoke goes out of his nostrils, as from a boiling pot and burning rushes.
²¹ His breath kindles coals, and a flame goes out of his mouth.
²² Strength dwells in his neck, and sorrow dances before him.
²³ The folds of his flesh are joined together; they are firm on him and cannot be moved.
²⁴ His heart is as hard as stone, even as hard as the lower millstone.
²⁵ When he raises himself up, the mighty are afraid; because of his crashings they are beside themselves. ²⁶ Though the sword reaches him, it cannot avail; nor does spear, dart, or javelin.
²⁷ He regards iron as straw, and bronze as rotten wood.
²⁸ The arrow cannot make him flee; slingstones become like stubble to him.
²⁹ Darts are regarded as straw; he laughs at the threat of javelins.
³⁰ His undersides are like sharp potsherds; he spreads pointed marks in the mire.
³¹ He makes the deep boil like a pot; he makes the sea like a pot of ointment.
³² He leaves a shining wake behind him; one would think the deep had white hair.
³³ On earth there is nothing like him, which is made without fear.
³⁴ He beholds every high thing; he is king over all the children of pride.”

Isaiah 30:6   The burden against the beasts of the South. Through a land of trouble and anguish, from which came the lioness and lion, the viper and fiery flying serpent …

From the descriptions above, one would have to admit that it certainly seems as if dinosaurs were seen on the earth, and described in the Bible. Whether God allowed them on the ark with Noah, or destroyed them all in the flood, the Bible does not tell us.

I hope that this makes sense to you. God bless!