Deserts and semi-deserts are vast open spaces with sandy, gravel, or clay soil. The main distinguishing features of these corners of the Earth are extremely low annual rainfall and high temperatures. During the day, the temperature can change dramatically. In deserts, intolerable heat (above +50°C) may be present during the day, and frost (temperature can drop below 0°C) at night. There can also be great temperature fluctuations throughout the year. In semi-deserts, temperature fluctuations are not so drastic, and the level of precipitation is higher.

Extreme conditions leave their mark on local flora and fauna. Vegetation in semi-deserts is usually sparse, and in deserts, it may be almost completely absent. Spore-reproducing plants, such as ferns, are unable to survive in such a harsh climate. Therefore, in Triassic deserts and semi-deserts, one could mainly encounter gymnosperms - conifers, cycads, and bennettitales (Wielandiella). Occasionally, seed ferns (Xylopteris) were encoun...