Shenacanthus combines chondrichthyan and armoured traits
The sole near-complete holotype IVPP V300000 records a roughly 436 Ma total-group chondrichthyan body with minute scales and a chondrichthyan-like branchial region but unexpectedly large thoracic armour plates; the exact stem position remains analysis-sensitive.
Represented range436–436 Ma
RegionsHuixingshao Formation, Yongdong, Xiushan, Chongqing, China
The sole near-complete Shenacanthus vermiformis holotype IVPP V300000 from the approximately 436 Ma Huixingshao Formation combines minute scales, absence of facial dermal bones and a chondrichthyan-like posterior branchial region with large thoracic armour plates; it is total-group chondrichthyan evidence, not a crown-shark diagnosis or a global Chondrichthyes FAD.