* Mudstone is not a preservative: Mudstone is a sedimentary rock formed from fine-grained mud and clay. It doesn't have the properties necessary to prevent decay.
* Decay is a natural process: All organic matter, including fish, decomposes over time, especially in the presence of oxygen and bacteria.
* Fossil formation requires specific conditions: Fossil formation is a rare occurrence that requires a unique set of circumstances. For a fish to become fossilized in mudstone, it would need to:
* Be buried quickly: This prevents scavengers and decomposition from destroying the remains.
* Be in an environment with low oxygen: This slows down the decay process.
* Be exposed to minerals: Minerals in the surrounding sediment can gradually replace the fish's organic material, preserving its shape as a fossil.
In summary: It's extremely unlikely for a fish to simply "not decay" in mudstone rock. While fossilization can occur in mudstone, it's a complex process that requires specific conditions.
