Clionolithes pannosus ( Solle, 1938 ) Wisshak, 2017

Wisshak, Max, 2017, Taming an ichnotaxonomical Pandora’s box: revision of dendritic and rosetted microborings (ichnofamily: Dendrinidae), European Journal of Taxonomy 390, pp. 1-99 : 29-30

Clionolithes pannosus ( Solle, 1938) comb. nov.

Fig. 7

Olkenbachia pannosa Solle, 1938: 164 , figs 17–18.

Platydendrina platycentrum Vogel et al., 1987: 274 , fig. 7.

Olkenbachia hirsuta – Solle 1938 (partim): 162, figs 9, 15, 17–18 (figs 2–4, 8, 11, 14 = C. radicans , figs 5–7, 10 = C. cervicornis and fig. 13 = Nododendrina nodosa ).

Olkenbachia sp. – Solle 1938: fig. 15.

Platydendrina – Vogel 1987: fig. 6.

Nododendrina convexa – (?) Thuy et al. 2014: fig. 1h .

Original diagnosis

Von einem relativ grossen, unregelmässig-lappigen Zentral-Hohlraum laufen kurze, breite, gebogene, nur wenig oder gar nicht verzweigte, in kurze Spitzen ausgezogene Gänge aus. [Translation: from a relatively large, irregularly-lobed central cavity, short, wide, bent, slightly branched or unbranched galleries with short pointed terminations emerge.]

Emended diagnosis

From a flat and irregularly-lobed central cavity with a smooth surface, short and rapidly tapering galleries emerge, which are little ramified, may form anastomoses, end in short pointed terminations, and connect to the substrate surface by short spiny outgrowths.

Original description

The central cavity exhibits an irregularly-lobed shape and is relatively large with 1 mm in longest diameter and 0.6 mm in maximum width. From this central cavity irregular, short, wide, bent, rarely nearly straight galleries emerge in all directions, none of which surpass the diameter of the main cavities in length. Only few of these galleries branch once or twice; they terminate in short pointed ends. The diameter of the branches exceeds 0.2 mm. The overall appearance of the trace is plump. [Translated from German]

Supplementary description

(Note: numbers in square brackets indicate n = number of specimens measured.) The detailed original diagnosis of the junior synonym Platydendrina platycentrum by Vogel et al. (1987) adds the following observations and morphometrical data: “Palmate, repeatedly branched system, up to 3 mm (1.03 ± 0.56 [16]) in diameter. Central area is occupied by a large flat surface that gradually grades into the branches. Branches diverge at angles ranging from 32° to 100° (58 ± 16 [58]). The margins between branches are scalloped forming deep rounded embayments. The width of the primary branches at the base is 50–300 µm (134 ± 63 [66]), the secondary branches 20–60 µm (40 ± 11 [82]), whereas the tertiary (distal) branches are 5–20 µm (16 ± 8 [54]). Thus, there is a substantial decrease in width from the proximal to the distal branches. The branches end with tiny rhizoidal appendages only a few micrometres wide, which connect to the substrate surface. The anastomoses are common sometimes leaving rounded holes. The branches are depressed in cross section. The dorsal surfaces (interior with respect to the shell) of Platydendrina are smooth, whereas its ventral side is beset by spiny outgrowths that connect to the substrate surface.”

Type material, locality and horizon

The holotype ( Fig. 7 A–C) is preserved as a natural cast in a brachiopod shell from the Flaser-Schiefer, Kondel-Gruppe, Oberkoblenz, Devonian, from Brodenbach Valley near the river Mosel in a small quarry opposite the Teufelslei near Münstermaifeld, Germany. Deposited in the brachiopod collection at the Senckenberg Institute in Frankfurt, Germany ( SMF XXVI 166a).

Remarks

Originally established within the ichnogenus Olkenbachia , which is a junior synonym of Clionolithes . The spelling has been changed to the masculine pannosus in order to be consistent with the ichnogenus in gender.

Compared to the other ichnospecies of Clionolithes , C. pannosus exhibits the shortest and least ramified galleries and the relatively largest and distinctly flat central cavity. In contrast to most other ichnospecies it may anastomose. Among all Clionolithes , the overall morphological appearance of this trace is closest to that of Dendrina .

Figures

Fig. 7. Clionolithes pannosus (Solle, 1938) comb. nov. A. Holotype preserved as natural cast in a Devonian brachiopod shell from the Mosel Valley near Münstermaifeld, Germany. B–C. SEM overview and close-up of the holotype. D–F. SEM planar view, oblique view and close-up of pyritised and resinembedded holotype of junior synonym Platydendrina platycentrum Vogel et al., 1987 in a shell of Mediospirifer Bublichenko, 1959 from the Middle Devonian of New York State, USA.

Fig. 1 (page 7). Morphological characters of dendrinid microborings with respect to overall shape and symmetry of the trace, its vertical profile, openings to the substrate surface, orientation of entrance tunnel (where present), branching pattern and surface texture (in order of decreasing relevance as ichnotaxobase).