I know the answer the answer to that is the answer will be trace fossil
I don't know if this helps or not but you would want to know the age of the rock (absolute dating) and from there you will be able to know the age of the fossil and what caused it to die.
I believe he is looking for an allele
An allele is a variant form of a gene. Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosomes. Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent.
Alcohol is a solvent and it basically dissolves anything. A lead is spongy and full of holes. When the leaf is mixed with alcohol, the alcohol affects the leaves. The alcohol melts the pigments of the leaf, chlorophyll, which is the green part. This will turn the alcohol green
