Comment on: The ichnogenus Lumbricaria Münster from the Upper Jurassic of Germany interpreted as faecal strings of ammonites

In their contribution, Knaust & Hoffmann (2021) discussed the interpretation of the genus Lumbricaria using several specimens from different collections. Lumbricaria is a coprolite first described by Münster (in Goldfuss 1831) from the Upper Jurassic lithographic limestones of Germany. It is characterized by a contorted, wormlike form of calcitic composition. Until now, for all the known records of the accepted ichnospecies of Lumbricaria (L. intestinum and L. colon), these remains consist of saccocomid ossicles. Various origins and producers have been attributed to Lumbricaria (see Janicke 1970). So far specimens that undoubtedly fulfil this definition have been reported only from Germany, where they were attributed to ammonite faeces (e.g. Janicke 1970; Schweigert 2001) and Argentina, where various lines of evidence point to a possible holothuroid producer (Kietzmann & Bressan 2019). On the other hand, Haude (2019) reported a coprolite composed of holothurian sclerites from the Early Jurassic of Germany, which was included as Lumbricaria by Knaust & Hoffmann (2021). Haude (2019) interpreted these coprolites as having been produced by a worm-like predator. We acknowledge that the data presented by Knaust & Hoffmann (2021) are important for the interpretation of the producer of this coprolite, and particularly those from Germany. When comparing with the material from Argentina, however, the authors misreported our paper. The aim of this comment is to correct some of the reinterpretations made by Knaust & Hoffmann (2021)..