The Early Jurassic featured extensive global desert systems that are exemplified in southern Africa by the Lower Jurassic Clarens Formation, the youngest sedimentary unit of the Karoo Supergroup. This Sinemurian to Pliensbachian formation consists of thick massive sandstone beds and large-scale cross-bedded sandstones in its middle sections. Lenticular siltstones in the lower and upper parts suggest intermittent wet conditions. These vertical facies changes correspond to three, long- established stratigraphic zones, yet their palaeoenvironmental context within Early Jurassic Pangaean climate remains unclear. Field data show that massive structureless deposits (68 %) and aeolian dune deposits (20 %) dominate the formation, with minor ephemeral channel, sand sheet, and pluvial deposits. Unconfined fluvial and debris flow deposits are least common. During semi-arid phases, limited sediment availability and higher moisture restricted dunes to isolated fields and resulted in significant downwind loess plains and fluvial incursions from the basin's southern and eastern margins. In contrast, aridification increased sand-size sediment supply, expanding the dune field into a sand sea and displacing the marginal erg facies eastward. These spatiotemporal facies shifts in southern Pangaea align with a wet-dry-wet megacycle documented along the Tethyan margin in the north during the Sinemurian and Pliensbachian. The facies shifts are interpreted as indicators of global climatic influences on local sedimentation. The well-preserved aeolianites of the Clarens Formation provide key insights into ancient erg dynamics and modern dryland responses to global climate change.