The Late Ordovician Mass Extinction event (roughly 445 million years ago), one of the big five major extinctions, is characterized by a glacial phase followed by a post-glacial warmer phase. Faunas of brachiopods (shelly marine organisms) were affected by the mass extinction, but in the late Rhuddanian (about 441 million years ago; early Silurian), this group became more diverse, recovering from the drastic Late Ordovician event, and a clear change from Ordovician-type faunas to new Silurian-type faunas is clearly observed. In this paper, we discuss such a recovery fauna from the Niuchang Formation (about 441 million years ago), Wanzi section of Zhenxiong, northeastern Yunnan Province in South China. This faunal composition (26 species belonging to 25 genera) indicates shallow-water environments, although some deeper-water species are present, and a clear shift from the previous fauna that was characteristic of post-glaciation shallow-water environments. The presence of such a fauna, only occurring in the early Silurian, indicates that the recovery of the brachiopod faunas after the Late Ordovician extinction took some time to become significant. Throughout the studied section, the succession of brachiopod species found indicates a shallowing of the marine environment, in contrast with the global deepening trend because of local tectonic uplift, which provided a stable environment where faunas could develop and thrive. Finally, the presence of species from the pentameride group of brachiopods, such as the oldest record of the large Sinostricklandiella, indicates diversification of this group, earlier than previously thought.

Following the Late Ordovician Mass Extinction event, brachiopod faunas were in a phase of recovery during the late Rhuddanian (early Silurian), documented by a drastic turnover of Ordovician-type to Silurian-type faunas. In this study, we present a recovery brachiopod fauna, from the Niuchang Formation (late Rhuddanian-based graptolite zonation) at the Wanzi section of Zhenxiong in northeastern Yunnan Province, South China. The fossils include 26 species assigned to 25 genera, with a dominance of strophomenides and orthides, but also a diverse suite of atrypides and pentamerides, which exhibit compositional differences compared to the earlier Edgewood–Cathay fauna. The emergence of a more typical Silurian brachiopod fauna suggests a delayed community turnover after the Late Ordovician Mass Extinction event. The shallowing marine environment trend evinced in the brachiopod assemblages in the section indicates a balance between the global transgression and the regional Qianzhong Uplift, which provided a stable environment for the brachiopod recovery. The presence of diverse pentamerides, including the earliest species of the large-shelled genus Sinostricklandiella, suggests early diversification of this clade in South China.