Article: Re-evaluation of the ichnogenus Helminthopis – a new look at the type material

The type material of Helminthopsis Heer, 1877 has been examined. The ichnospecies established by Heer (1877) are unsuitable for representing this ichnogenus. Helminthopsis magna (subsequently designated type ichnospecies by several authors) and Helminthopsis intermedia are specimens of Scolicia isp. de Quatrefages, 1849, while Helminthopsis labyrinthica is a three-dimensionally complex graphoglyptid quite unlike Helminthopsis auctt. and very similar to Spirocosmorhaphe helicoidea Seilacher, 1989. However, because of its popularity and its distinctive morphology, and in the interests of nomenclatural stability, Helminthopsis is retained by erecting a new ichnospecies on the basis of material in Heer's collection. Helminthopsis hieroglyphica isp. nov., although never formally published by Heer (only in litteris), was labelled as such by him in his collection, and is proposed here as the type ichnospecies. Helminthopsis is normally preserved in hyporelief, but seldom in full relief. Trace fossils in full relief preservation having a morphology similar to Helminthopsis were grouped into the (ichno)genus Theobaldia by Heer (1877). Although Theobaldia has page priority over Helminthopsis, the name has hardly ever been used and we declare Theobaldia an abandoned senior synonym in order to maintain nomenclatural stability.