The ichnological collection of Georg Gasser (1857–1931): between fucoids and trace fossils

At the end of the 19th century, the naturalist and artist Georg Gasser assembled a rich palaeontological collection, which included several trace fossils. The collection consists of 56 ichnological specimens, which were interpreted either as body or trace fossils by Georg Gasser. Specifically, a conspicuous part of the collection is represented by the dwelling burrow Laevicyclus parvus,
which was interpreted as a crinoid columnal (“Trochiten”). By contrast, Gasser correctly interpreted the feeding burrow Planolites beverleyensis as a trace fossil (“Hieroglyph”), although some specimens were interpreted as body fossils. Gasser supported the botanical interpretation for the burrows Chondrites intricatus and Gyrochorte comosa, which were considered as a seaweed and a
conifer, respectively. The collection of Gasser also includes a well-preserved ophiuroid burrow (Asteriacites lumbricalis), the fecal string of an ammonite or a holothurian (Lumbricaria intestinum), and possible fish coprolites. The mixed interpretation of Gasser reflects his historical period, during which discussion over the botanical or ichnological nature of trace fossils took on increasing
prominence among scientists. Revision of the collection shows that the collection is dominated by trace fossils of the Werfen Formation (Lower Triassic), which indicates that Gasser assembled its ichnological collection without a specific stratigraphic criterion.