16 which fossil would be the worst choice for an index fossil? a fern b ammonite c trilobite d gastropod

Answer

Brief Explanations:

Index fossils are used to date rock layers and are characterized by having a wide - spread distribution and a short stratigraphic range. Ferns are plants that have a long evolutionary history and a relatively wide and continuous distribution over time, making them less useful as index fossils compared to the others. Ammonites, trilobites, and gastropods have more distinct time - bound distributions and are better for indexing rock layers.

Answer:

A. Fern