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1. The fossil records of the marine dwelling organisms are relatively common. As the aquatic species die their body falls to the bottom of the sea. These dead bodies get buried in the sediments in comparison to the terrestrial species. Due to this the decomposition process of the marine species gets slow down, and thus, are found commonly in fossil records.  

2. The fossil records of desert-dwelling species are relatively rare. As the body of the dead desert animal remains upon the sand until it gets buried naturally, which is a time-consuming procedure. This time is enough for the microorganisms to act as decomposers. Thus, fossil formation becomes rare.  

3. The fossil records of flowers are relatively common. It is due to the fact that the flowers comprise pollen grains and the pollen grains exhibit hard outer covering formed of two layers.  

4. The fossil records of the recent organisms are found commonly. The fossils of species that were found millions of years ago are more likely to be found in the rocks. As the species get buried between the rocks, therefore, the oxygen is very negligible or low in order to decompose the body of the species. The fossils present in the rocks get eroded with time or gets transformed into other forms due to heat or pressure.