Dendrina lacerata Hofmann 1996
Creators: name: Wisshak, Max
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Dendrinidae
Dendrina
Dendrina lacerata

description: Dendrina lacerata Hofmann, 1996
Fig. 4
Dendrina lacerata Hofmann, 1996 (partim): 78, pl. 8, figs 3–6.
Piatella-Form – (?) Bundschuh 2000: 69, pl. 10, figs 1–3.
Original diagnosis
Rosettenförmiges Gangsystem mit sehr breiten und zerlappten Gangformen, häufigen Verschmelzungen einzelner oder mehrerer Gänge und nur wenigen Gangverzweigungen. [Translation: Rosetted boring system with very wide and lobed galleries, common fusion of individual or multiple galleries, and only few ramifications]
Emended diagnosis
Rosette of irregular outline and with wide and lobed galleries, common fusion, and only few ramifications. Inlet tunnel relatively short and often entirely obscured by the rosette.
Original description
The trace shows, similar to Dendrina orbiculata nov. ichnosp., a distinct central area of 0.5 to 1.2 mm in diameter (mean 0.67 mm). For the entire rosette diameters of 1.1 to 2.5 mm (mean 1.72 mm) were measured. Characteristic for this form are the very thick, in planar view irregularly-shaped galleries emerging from the central area. These have a distinctly oval cross section with a 240 to 500 µm lateral diameter. Anastomoses and fusion of individual or several galleries are common, whereas branching points are rare. If present, branching is dichotomous. Gallery terminations are rounded. Due to the anastomoses and gallery fusion, the distal galleries of Dendrina lacerata nov. ichnosp. often have larger diameters compared to the proximal ones. Typical for this boring system is furthermore their stacked occurrence and interconnection with tunnels. Galleries connecting to the substrate surface are present at least at the periphery of the rosette (diameter 20 to 40 µm). The entire rosette is developed about 40 to 100 µm below the surface of the belemnite rostrum. [Translated from German]
Supplementary description
Dendrina lacerata is often found connected to the periphery of Calcideletrix anomala or C. flexuosa, forming a composite trace fossil (Fig. 4C and separate section below).
Type material, locality and horizon
The holotype (Fig. 4A) is preserved in an epoxy resin cast of a Belemnitella mucronata rostrum from the upper Campanian stobaei/basiplana Zone, sampled in the Germania IV quarry near Misburg, Germany. One paratype (Fig. 4B) is found on the same and further paratypes (e.g., Fig. 4C) on three other epoxy casts from belemnite rostra sampled at the type locality and from an outcrop near Lägerdorf, Germany.
Remarks
A similar form, but either with or without a very thick inlet tunnel, was informally described as Piatella-Form by Bundschuh (2000), potentially extending the stratigraphic record of this ichnospecies and for the ichnogenus to the Silurian, although this assignment is made only tentatively here.
Dendrina lacerata is somewhat smaller in diameter than the two other ichnospecies of Dendrina and in contrast to them it exhibits only a few and much wider lobes, rather than individual or fused galleries. The inlet tunnel usually is less pronounced and shorter than in the other two ichnospecies.
description: Published as part of Wisshak, Max, 2017, Taming an ichnotaxonomical Pandora's box: revision of dendritic and rosetted microborings (ichnofamily: Dendrinidae), pp. 1-99 in European Journal of Taxonomy 390 (390) on pages 21-23, DOI: 10.5852/ejt.2017.390, http://zenodo.org/record/3839858