Dactyloidites Hall, 1866

Uchman, Alfred & Pervesler, Peter, 2007, Palaeobiological and palaeonvironmental significance of the Pliocene trace fossil Dactyloidites peniculus, Acta Palaeontologica Polonica 52 (4), pp. 799-808 : 800

Ichnogenus Dactyloidites Hall, 1866

Type ichnospecies:? Buthotrephis asteroides Fitch, 1850 ; Lower Cambrian , New York State, USA .

Diagnosis.—Vertical radial spreiten structure having central shaft ( Fürsich and Bromley 1985).

Remarks.—The ichnogenus Dactyloidites Hall, 1866 was reinterpreted by Fürsich and Bromley (1985). They included Brooksella Walcott, 1896 and Haentzschelinia Vialov, 1964 in this ichnogenus and recognized three ichnospecies of Dactyloidites : D. asteroides Fitch, 1850 , D. canyonensis Bassler, 1941 , D. ottoi ( Geinitz, 1849) . D. peniculus D’Alessandro and Bromley, 1986 , and D. cabanasi (Meléndez in Cabanás, 1966) (see Gámez Vintaned et al. 2006 for the latter) were distinguished latter. Fürsich and Bromley (1985) interpreted Dactyloidites as a structure produced by worm−like organisms having a proboscis used for reworking sediment from a central shaft.

It seems that trace fossils described under Dactyloidites Hall, 1866 require a revision. First of all, the type material of the type ichnospecies (Lower Cambrian of New York State), which displays only a few rays of uneven width (see Häntzschel 1975: fig. W88.7), requires a revision, but this was never done. Vialov (1989) expressed his opinion that Haentzschelinia Vialov, 1964 should be excluded from Dactyloidites sensu Fürsich and Bromley (1985) , foremost because of the fact that the radial elements of Haentzschelinia, in contrast to those of Dactyloidites , are numerous and of constant width. Vialov (1989) argued also that Dactyloidites is much larger and that its type material is confined to the Cambrian. Also Schweigert (1998) separated Haentzschelinia and Dactyloidites on the basis that Dactyloidites is a fully radial star−shaped trace fossil and Haentzschelinia forms commonly only a half or three quarters of a star. The diagnosis of Dactyloidites by Fürsich and Bromley (1985) accentuates spreiten, however in D. peniculus (see the diagnosis and description below) only spreite−like structures are present. It is not excluded that the diagnosis of Dactyloidites should be amended or D. peniculus should be ascribed to different ichnogenus. All these problems are, however, beyond the scope of this paper and cannot be resolved without re−evaluating the type material of Dactyloidites .