What could explain the distribution of mesosaurus fossils

The Mesosaurus fossils were distributed in different parts of the world such as South America and South Africa. This fossil was a freshwater organism, a lizard-type reptile and their presence in different places were an evidence which suggested that the continents were once all together, supporting the continental drift theory. As it was too difficult to swim across this huge water body, so the same type fossils are found at two different continents.

The coastlines of South America and South Africa also perfectly fits one another.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.

your spelling is a little off : ]