It would be that they are made from cooling of lava or magma because they form from magma underground unlike sedimentary rocks
It increases genetic diversity by introducing alleles from one population into another.
Answer:
Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed.
Explanation:
A trilobite. Trilobites became extinct about 250 million years ago while a ammonite became extinct around the same time as dinosaurs(65 million years ago). You wouldn't find a human skull or a dinosaur footprint
