I’ve read that the Jurassic Park method of bugs and amber doesn’t work. Is there any realistic (or even fairly plausible) way to get dino DNA?
A possibility:
They managed to find some preserved soft tissue in Sue, and I think they even extracted some DNA from it. Not nearly enough to clone a T. rex from, of course, but some.
And I was going to be a wise-ass and link to an article about cloned birds, except that it turns out that there aren’t any. Apparently, the egg yolk makes it much more difficult to clone birds than mammals.
So it looks like I’m never going to rule the world with my army of cyborg T-rexes. 
…with frickin laser beams on their heads.
I thought there was a time limit on how long intact DNA lasts? While it may be possible to get something from ice-age animals, maybe, that’s only a few tens of thousands of years, tops. Dino DNA would be 65+ million years older, so it seems unlikely.
…psst…psst…meet me in the alley behind Moe’s Tavern…I got some Suchasaurus Chromosomes that will mess you up.
Bring cash.
I’d read somewhere that even under “preserved in amber” or similarly extreme circumstances, a million years was the best you were going to get. 65 million years ain’t happening, and that’s still only the very latest dinosaurs. I mean, at least that includes T. Rexes and Triceratopseses, but if you want a Stegosaurus that’s another 80 million years’ time gap.
The oldest recovered DNA is from northern Greenland and dates to 2.4 million years ago.
Obviously a highly specialised environment has helped to preserve it for much of that time, and the DNA is itself fragmentary, intact enough to characterise what plants and animals it comes from but not enough for fancy propagation.
DNA degrades over time, and animal remains themselves become scarcer with time esp as climates change, land erodes. Only a tiny fraction of animals get fossilised, a much tinier fraction of them would die in environments that will remain stable enough to preserve DNA. That’s why amber has such potential, sealing the animals that fed off bigger animals from further decay. There is amber with bugs dating throughout the Mesozoic, and we even have a lizard from 99 million years ago.
The convergence of a dinosaur dying in the right way so a bit of it falls into tree resin, that turns into amber, its DNA doesnt degrade further and environmental longevity preserves the amber into the present has a teeny-weeny probability, but is not zero.