A description of a fire-breathing monster ("leviathan") is given in the book of Job 40:20 - 41:25. Sounds pretty much like a dragon to me.
Job 40
20 Canst thou draw out the
leviathan with a hook, or canst thou tie his tongue with a cord?
...
etc...
A leviathan is a sea monster. The Bible uses the term "dragon" to refer to Satan.
But you are drifting off-topic and ignoring the point under discussion. You said, "When one of their fossils is discovered, evolutionists will have to fit it somehow into their mythical Tree of Life," and the answer remains the same. When the fossil of a dragon or minotaur or griffin or crocoduck is discovered then it will throw a major monkey wrench into the theory of evolution. Just finding a rabbit fossil in the Cambrian would do the same.
--Percy