* High energy environment: Conglomerates form in high-energy environments like fast-flowing rivers, glacial deposits, or storm waves. The strong currents and powerful forces involved in these environments tend to break and erode fossils, making them less likely to be preserved.

* Large clasts: Conglomerates are characterized by large, rounded clasts (fragments of rock) that are cemented together. These clasts themselves can be quite large, sometimes even exceeding the size of a human head! If a fossil happens to be embedded in one of these large clasts, it will likely be broken apart or obscured.

* Lack of fine-grained sediment: Conglomerates often lack the fine-grained sediment (like mud or silt) needed for preserving delicate fossil structures. This is because the energy levels required for conglomerate formation tend to wash away finer sediments, leaving only the larger clasts behind.

* Erosion and reworking: Conglomerates can often be reworked deposits, meaning they consist of materials that have been eroded from older rock formations and re-deposited. This means fossils within the conglomerate may have been fragmented, weathered, or even destroyed during the process.

While fossils are less common in conglomerates, they can sometimes be found. It's more likely to find highly durable fossils, like teeth, bones, or shells, that can withstand the rigors of transportation and deposition in these energetic environments.