Permian Extinction: Fossil Survival Analysis

The question asks to identify fossils that were completely extinct by the end of the Permian period. This period ended with the Permian-Triassic extinction event, the most severe extinction event in Earth's history.

Fossil Group Analysis

• Favosites: These are extinct genera of tabulate corals. Tabulate corals, as a group, suffered massive losses during the Permian-Triassic extinction and are considered completely extinct by its end.
• Phacops: This is an extinct genus of trilobites. Trilobites were a diverse group of arthropods, but most families, including those represented by genera like Phacops, went extinct at the end of the Permian.
• Aulacopleura: Similar to Phacops, Aulacopleura is another extinct genus belonging to the trilobites. Its lineage also ended with the Permian extinction.
• Lingula: This genus represents brachiopods. Brachiopods are marine animals known for their exceptionally long fossil record. Lingula is often referred to as a "living fossil" because it survived the Permian extinction and its modern descendants still exist today.

Conclusion on Extinction

Based on the analysis:

• Favosites became extinct by the end of the Permian.
• Phacops became extinct by the end of the Permian.
• Aulacopleura became extinct by the end of the Permian.
• Lingula survived the Permian extinction.

Therefore, the fossils completely extinct by the end of the Permian are Favosites, Phacops, and Aulacopleura.