Аннотация:Abstract A single slab of silicified silty and cross-bedded mudstone from the Katkoyeh Formation, east-central Iran yields Yutagraptus cf. mantuanus Riva which indicates a late Arenig age. The slab also bears Dictyonema ghodsiae sp. nov., regarded as the only unequivocally planktonic dendroid from post-Tremadoc strata. The sicula is surrounded by at least twelve vesicular bodies which constitute a raft of floats. These are the only certain floats yet identified in the Order Dendroidea, and one of very few cases known in the Class Graptolithina.