The question asks about which types of fossil remains are studied within the branch of geology known as ichnology.
Ichnology is specifically the study of trace fossils, which are geological records of biological activity. These are not the direct remains of organisms, such as bones or shells, but rather the evidence of their activity. The primary types of trace fossils are:
Given this, the correct answer is:
The other options do not relate to ichnology:
In conclusion, ichnology is concerned primarily with analyzing physical evidence of an organism’s behavior, such as tracks, trails, burrows, and bioturbation, rather than the remains of the organism itself.
| Group I | Group II |
| P. Dissepiment | 1. Echinodermata |
| Q. Delthyrium | 2. Trilobita |
| R. Pygidium | 3. Brachiopoda |
| S. Ambulacrum | 4. Anthozoa |