@vikorr,
The diprotodon was a megafauna class mammal like the mammoth or wooly rhino.
The Old Testament of the bible is a sort of a Readers' Digest version of what Jewish scholars call 'midrashim', which is the full body of ancient rabbinical literature and includes both fuller descriptions of OT stories and books which didn't make it into the Bible. The largest compilation of such which has been translated into Western languages is Louis Ginzberg's 7-volume Legends of the Jews which used to be hard to get any sort of a look at but which is online now.
"Legends" describes several kinds of things which are clearly dinosaurs but it's clear that what is being described is just a handful of leftovers walking around at a time prior to the flood. American Indian traditions describe Indian ancestors having to deal with dinosaurs and megafauna both on a much more regular basis and some of these appear in Amerind artwork and petroglyphs. The most obvious case is the stegosaur, of "Mishipishoo" in Ojibway language. Lewis and Clark described their Indian guides as being in mortal terror of Mishipihu glyphs around the Mississippi (name are related) river and a few of such glyphs still exist, the best preserved being the one at Agawa Rock, Massinaw, Lake Ontario:
Indians have always been in the habit of touching those glyphs up every couple of decades or so and the horns were added long after the stegosaur died out, but you can see the dorsal spikes which no modern animal which looks anything remotely like that has. Amerind traditions describe Mishipishoo as havin gred fur, a sawblade back, and a spiked tail which he used as a weapon. Best source is Vine Deloria's "Red Earth, White Lies".