A chasmataspidid affinity for the putative xiphosuran Kiaeria Størmer, 1934

The putative xiphosuran Kiaeria Størmer, 1934, from the Late Silurian (Ludlow) of Ringerike, Norway, is redescribed from the holotype and only known specimen as a chasmataspidid chelicerate arthropod. Morphological features such as the presence of a fused buckler of three opisthosomal segments clearly indicate a chasmataspidid afnity, while the size of Kiaeria, along with the occurrence of a raised axial region and expanded anterior articulation, suggest a close phylogenetic relationship to the Ordovician Chasmataspis. As such, Kiaeria represents the frst indication that the Chasmataspis-type chasmataspidid morphology persisted alongside the radiation of diploaspidids. This is also only the third chasmataspidid species recorded from the Silurian.