“Explain to me how this piece of animal tissue is evidence of a young Earth.”
Maybe you can explain how they dated this piece of animal tissue at 80 million (give or take a few days) years old?
I don't konw how they dated it. I do know how they date the age of the Earth, and it isn't with dinosaur bones.
Hadrosaurs are found in rocks formed during the Cretaceous Period. Cretaceous rocks have been dated to from 150 to 65 million years ago by the decay of radioisotopes. Radiometric dating on the geologic scale has been tested against the processes shaping the Earth itself, such as sea floor spreading, and been found reliable. While the scientists may not have dated this particular duckbill, they have dated enough members of the family to get a pretty good idea of when they existed.
And I haven't read any serious reporting on this yet, just the press release, but I doubt the researchers reported "a few days" as their margin of error. Any scientific style guide will tell you to use numbers (e.g. +/- four days).