In Canada, as well as in Denmark, amino acids that are not known to exist anywhere else on Earth were discovered in the layers. This evidence had the interesting feature that it favored a comet interpretation, since these amino acids were found in the bordering limestone as well—as would be the case if comet dust were around at the time the layer was formed.
The amino acids are far more interesting than rehashed 30-40 year old science that I already know.
