44 / 2025-03-28 16:28:33

Clonal Budding and Sessile Stalk of Conulariids Revealed by a Chinese New Genus

conulariids,budding,sessile stalk,Silurian,South China

Theme 3: Earth-Life Co-evolution Through Time > Session 3a: Precambrian Earth and Life Co-evolution

A new genus, Sericonularia n.gen., is established here based on lower Silurian conulariid fossils collected from Wuhan, China. This genus is distinguished from other conulariids by extremely thin transverse ribs, thick septa along the corners of the faces, and flat interspaces. The reproductive mode and the sessile stalk of conulariids have been long controversial. In this study, the holotype of the type species Sericonularia gemmata n. gen. et n. sp. provides new clues about budding reproduction in conulariids; moreover, this exceptional specimen offers a unique perspective on the structure and morphology of the sessile stalk. We hypothesize that, once the budding larvae could live independently, they would have detached from their parent and then found a vantage point to attach; notably, some conulariids would have used sessile stalks, rather than discs, during their sessile life phase. These stalks appear to have the same structure as the upper periderm. Overall, our observations provide new valuable insights on conulariid affinities and lifestyle.