River floodplains are expansive lowland areas stretching along the course of a river. They become a place for the spread of river water during periods of seasonal floods or heavy rains.

In river valleys, after a change in the river course, parts of the riverbed with standing water - old river beds or oxbow lakes - may remain. Some of these turn into independent lakes or swamps. Sometimes, part of the soil on the river banks also becomes marshy. For this reason, the animal and plant life of the river floodplain, lakes, and swamps can quite strongly overlap and even have common elements.

The main feature of river floodplains is their ability to retain a large amount of moisture. In addition, alluvial soils are very fertile. This creates favorable conditions for plant growth and the existence of a high variety of animals.

On the banks of Jurassic period rivers, one could encounter horsetails, ferns such as Dictyophyllum, clubmosses, and mosses. As in the Triassic, the dominant tr...