Leviathan = Sarcosuchus?
In Job 40, in response to Job's questioning of God's wisdom, God sets out his credentials and challenges Job to answer a 77-question "creation science" exam. He says to Job, "brace yourself like a man; I will question you, and you shall answer me."
The exam covers the breadth of God's creative power, mentioning the wonders of many animals that we are familiar with such as the lion, raven, deer, ox and ostrich.
Finally, there is "Leviathan" -- a terrifying aquatic creature with an impenetrable hide impervious to harpoons, fearsome teeth and a back covered in rows of shields. It even has firebrands streaming from its mouth and smoke from its nostrils.
Though this may sound mythological to us, Job recognized it as a real creature. Indeed, one candidate from the fossil record is Sarcosuchus, a 12-metre (or 40 foot) monster with an unusual bulbous cavity at the end of its snout that could conceivably have been used for mixing fire-generating chemicals.