Dude, rhino’s are still around. A unicorn is not a rhino, ask my daughter. Still this particular specimen went extinct 30,000 years ago, about 20,000 years before the first writing, about 25,000 years before the predecessor to the modern Bible even started to be written.
Your posts, as always, are based on very poor understanding of the science, in this case differences between DNA, RNA and the nucleotides they are composed of and which, if any, remnants are recovered. Complete DNA strains that are thousands or millions of years old is ludicrous, it’s lazy reporting at best, but scientifically dishonest if anyone calling themselves having a doctorate wrote it in a book. Things decompose even when they are frozen, sometimes slower, sometimes faster, but useful DNA strains break down very quickly, the individual components (eg. the equivalent to sugar) does not. You can often recover evidence of DNA/RNA components without it being useful/complete DNA/RNA. Likewise some organisms can survive really long, perhaps even indefinite in some circumstances, that doesn’t prove anything. But I’m not giving you yet another biology lesson, finish high school biology before engaging in these kinds of arguments.
If you want to make a point based on science that still adjusts claims in the scale of millions of years, it would not prove anything described happened in the last 8000 years which is the age of the earth as described in the Bible. So if you want to take the Bible literally (there are genealogy in the Bible that go from the 7th day of creation to 32AD) you can’t take the things you like from science that you mistakenly believe support your literal Bible interpretation. Job specifically was written ~2500 years ago, these beasts weren’t there, rhinos were and it is possible that is what they were talking about based on stories from traveling merchants, but you’d think a book written by a literal god would be a bit more specific.