Paleontology and ichnology of the late Ediacaran Nasep–Huns transition (Nama Group, southern Namibia)

Abstract The Nasep and Huns members of the Urusis Formation (Nama Group), southern Namibia, preserve some most diverse trace-fossil assemblages known from latest Ediacaran worldwide, including potentially world's oldest “complex” vertical sediment-penetrating burrows. These sediments record relatively communities bilaterian metazoans existing before base Cambrian an increase in intensity metazoan ecosystem engineering behaviors that could eventually produce profound changes character Phanerozoic sedimentary (the “agronomic revolution”). Despite this, little about this assemblage is known. We explore Nasep–Huns transition at two localities Witputs sub-basin describe trace- body-fossil diversity present these horizons alongside a paleoenvironmental reconstruction. document eight unique ichnotaxa localities, well-preserved “probes” left by priapulids. also report first occurrence Corumbella helping to establish biostratigraphic link between Brazil, Paraguay, Iran, southwestern United States. Last, we find several ichnotaxa, particular small treptichnids, appear be preferentially preserved on bases gutter casts, hinting potential existence unusual late preservational window with possible implications for timing appearance key behaviors.