How does a turd survive 270-300 million years? I know it's fossilized, but how'll g does that take.
Ooh! Ooh! I know this! Can I answer it?
You are exactly right in your assessment that something so squishy and full of organic matter shouldn't be preserved and last for millions of years. But these kinds of things happen! They happen in environments that allow for exceptional preservation. One such environment is a part of the deep ocean that has relatively low levels of oxygen at the bottom.
If you exposed a poop to air on land, it would be decomposed in a day. But in water, there are much fewer microbes that lead to the decomposition of the poop. And some places in the ocean have so little oxygen that the poop can stay on the bottom without much change and slowly get covered by fine-grained sediment until it lithifies and becomes a poop trapped in a rock.
But that poop has to become a rock like this Image: http://upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Pseudocoprolite.jpg/220px-Pseudocoprolite.jpg
to be a fossil and stay in the fossil record. That's where mineral rich waters in the pores of the sediment that trapped the poop come into play. Those minerals replace the organic matter until all that's left is something that is rich in iron, sulfur, or both to make a fossilized poop.
Then that fine-grain sediment it's in has to be weathered away preferentially over the (now) coprolite and voila, you have a lone shark poop as a fossil.
Can I turn one of my turds into a fossil?
Yup. Just like the poop in our example, you have to replace the organic soft stuff with hard stuff. You can cheat the system and use a whole bunch of salt, lime powder, or, heck, kitty litter almost could get you there. But keep in mind that most paleontologists only consider things older than 10,000 years to be fossils. So, I'd eat some mammoth burgers, then you could radiocarbon date that and prove it to be a fossil!