Question

in rock layers, jellyfish fossils are found lower than trilobite fossils, and trilobite fossils are found lower than ammonite fossils. what can be determined from this information?
trilobites existed before jellyfish and ammonites.
jellyfish existed before trilobites and ammonites.
ammonites existed before trilobites and jellyfish.
jellyfish, trilobites, and ammonites lived together.

Explanation:

In geology, fossils in lower rock - layers are generally older. Since jellyfish fossils are lower than trilobite fossils and trilobite fossils are lower than ammonite fossils, jellyfish existed before trilobites and ammonites.

Answer:

Jellyfish existed before trilobites and ammonites.