Calcideletrix anomala ( Mägdefrau, 1937 ) 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 : 39-41

Calcideletrix anomala ( Mägdefrau, 1937) comb. nov.

Fig. 13

Dendrina anomala Mägdefrau, 1937: 55 , pl. IV, fig. 5.

Dendrina – Radwański 1972 (partim): 257, figs 1–4 .

Dendrina anomala – (?) Marcinowski 1972: 247, pl. 1, fig. 2 (poor illustration). — (?) Kutscher 1972: 27, fig. 6. — Nestler 1975: 108, fig. 159c (reproduced from Quenstedt 1849). — Hofmann 1996:

67, pl. 5, figs 5–6, pl. 6, figs 1–2 , pl. 8, fig. 4. — (?) Košt’ák 2004: 32, fig. 6 (poor illustration). —

Rudolph 2014 (partim): 19, fig. 24 (specimen on right). — Breton et al. 2017: 46, fig. 3E. Rosetten-Form B – Hofmann & Vogel 1992: 56, pl. IV, fig. A. Calcidelatrix anomala – Plewes 1996: 189, pl. 33 fig. 8, pl. 35, figs 1–8 . Dendrina isp. – (?) Verde 2002: 46, pl. VI, fig. D (poor illustration). Dendrina (Calciteletrix) anomala – Girod & Rösner 2013: 280, fig. 13.

Original diagnosis

n/a

Emended diagnosis

Main branches may curve in a sinuous fashion and in small individuals may be devoid of smaller sidebranches along some length of the curve. From these closely prostrate main axes, with usually smooth surface texture, branches divide, may form anastomoses and gradually decrease in diameter to fine pointed ends that connect to the substrate surface.

Original description

Rosetted cavity system, strongly and regularly branching. Very conspicuous for this species are strongly varying gallery diameters, unlike all other forms described herein. While the main galleries may reach 0.7 mm in diameter, secondary branches may reach only 0.03 mm in diameter. [Translated from German]

Supplementary description

Based on additional material, including epoxy resin casts, Plewes (1996) added the observations that the main axis is often distinctly curved, branching is polychotomous or dichotomous, the surface texture is smooth and the ends of the many lateral and peripheral branches taper to fine points which intersect with the substrate surface. She provided morphometrical data for the width of the main axes (mean = 96 µm; n = 20; SD = 76.60) and secondary branches (mean = 35 µm; n= 18; SD = 15.28). Hofmann (1996) gave a size range of the trace of 2–6 mm and measured diameters of up to 180 µm for the main axes and 20 to 70 µm for the peripheral tunnels. In addition, he observed rare anastomoses.

Type material, locality and horizon

The holotype is preserved in a rostrum of an Actinocamax from the Upper Cretaceous of Misburg near Hannover, Germany. It used to be deposited at the collections of the Institut für Geowissenschaften und Geographie , Halle , Germany, where only the original glass negative ( MLU.Mäg1937.IV.5 ) presently remains ( Fig. 13A ). Consequently , another specimen ( Fig. 13 B–C) within the original material of Mägdefrau from the same type horizon and locality, on the same belemnite ( MLU.Mäg1937.IV.10 ) that carries the holotype of Dictyoporus nodosus Mägdefrau, 1937 , was selected as the neotype by Plewes (1996). Since the latter designation was not a valid nomenclatural act (unpublished thesis), this neotype designation is hereby formalised.

Remarks

This ichnospecies was originally established within the ichnogenus Dendrina by Mägdefrau (1937). However, Dendrina is morphologically very distinct and the ichnospecies shows typical characters intermediate between those of Clionolithes and Calcideletrix instead. Plewes (1996) consequently placed D. anomala within Calcideletrix (without discussion or designation as comb. nov. and misspelled as Calcidelatrix). Nevertheless, this synonymisation appears practical and is followed and formalised herein. Calcideletrix anomala is the largest among the suite of ichnospecies of Calcideletrix , and is morphologically closest to the related ichnogenus Clionolithes and in particularly C. radicans . It is clearly distinguished from the latter by the lack of a distinct central node, the common presence of anastomoses of the main galleries in the central area, and by its very gradual decrease in gallery diameter.

Figures

Fig. 13. Calcideletrix anomala (Mägdefrau, 1937) comb. nov. A. Original glass negative of the lost holotype from an Upper Cretaceous belemnite from Misburg, Germany. B–C. Overview and closeup of the neotype from the same type locality and horizon; the centre of the colony is partly obscured by a deeper tier of Dendrina ispp. D. A large specimen in a belemnite from the upper Campanian of Kronsmoor, Germany. E–F. SEM planar and oblique views of an epoxy cast of the same specimen.

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).

Fig. 2. Dendrina dendrina (Morris, 1851) comb. nov. A. Original illustration of belemnite with various traces, including D. dendrina (arrows; reproduced from Quenstedt 1849: pl. 30, fig. 36); provenance unresolved. B. Original amalgam, including D. dendrina (arrows and label “d”; reproduced from Quenstedt 1885: pl. 38, fig. 39). C. Re-illustration of original Quenstedt Dendrina (reproduced from Plewes 1996: pl. 22, fig. 5). D. Original illustrations of Talpina dendrina (= D. dendrina; reproduced from Morris 1851: pl. IV, figs 4–7; 5 = Talpina ramosa; 6a = Trypanites solitarius). E. Morris’ original belemnite from the Upper Cretaceous of Norfolk, UK, including the lectotype of D. dendrina (encircled). F–G. Close-up of lectotype under incipient and transparent light; the inlet canal is clearly visible. H–I. Three paralectotypes in the same belemnite. J–K. Planar and oblique views of the holotype of junior synonym D. fluensis Hofmann, 1996, illustrating the typical multi-tier occurrence, irregular branching, and meandering galleries; SEM of epoxy cast of a belemnite from the lower Maastrichtian at Kronsmoor, Germany. L. Holotype of junior synonym D. crassa Hofmann, 1996, within the morphological range of D. dendrina; SEM of epoxy cast of a belemnite from the lower Maastrichtian at Kronsmoor, Germany.

Fig. 3. Dendrina belemniticola Mägdefrau, 1937. A. Original illustration of belemnite with various traces including D. belemniticola (arrow; reproduced from Quenstedt 1849: pl. 30, fig. 36); provenance unresolved. B. Original amalgam, including D. belemniticola (arrow; reproduced from Quenstedt 1885: pl. 38, fig. 39). C. Re-illustration of original Quenstedt Dendrina (reproduced from Plewes 1996: pl. 22, fig. 3); inlet tunnel roughly at 11h in this and the following four sub-figures. D. Lectotype of D. belemniticola in an upper Senonian belemnite from Rosenthal near Peine, Germany (compare to Mägdefrau 1937: pl. IV, fig. 1). E. Holotype of junior synonym D. orbiculata Hofmann, 1996. SEM of epoxy cast of an upper Campanian belemnite from Lüneburg, Germany. F. Paratype of junior synonym D. constans Hofmann, 1996. SEM of epoxy cast of a lower Maastrichtian belemnite from Lüneburg, Germany. G. Holotype of junior synonym D. constans. SEM of epoxy cast of a lower Maastrichtian belemnite from Lüneburg, Germany. E–G illustrate the morphological range of D. belemniticola from almost completely fused radiating galleries, to partially fused galleries forming anastomoses, to rarely fused radiating galleries. H. Detail of partly obscured inlet tunnel connecting to centre of a paratype of junior synonym D. orbiculata. SEM of epoxy cast of an Upper Cretaceous belemnite from Lüneburg, Germany. I. Rarely observed overlap of D. belemniticola in a lower Maastrichtian belemnite from Rügen, Germany. J. Specimen of D. belemniticola (left) next to a D. dendrina (right) at the very tip of a lower Campanian belemnite from Höver, Germany.

Fig. 4. Dendrina lacerata Hofmann, 1996. A. SEM of holotype in an epoxy cast of an upper Campanian belemnite from Misburg, Germany. B. Paratype on the same cast as the holotype. C. Several paratypes in the periphery of a Calcideletrix anomala from the type locality. D. Oblique view of a specimen in a belemnite from the upper Campanian of Kronsmoor, Germany, illustrating a tubular inlet tunnel on the left and peripheral connections to the substrate surface on the right. E. Surface view of a solitary specimen with inlet canal in a belemnite from the upper Campanian of Misburg, Germany.

Fig. 5. Clionolithes radicans Clarke, 1908. A. Original illustration of the lectotype from the Devonian of Mansfield, Pennsylvania, USA (reproduced from Clarke 1908: pl. 11, fig. 1). B–C. Overview and close-up of a shell of the brachiopod Atrypa bearing the lectotype and a number of further specimens. D. Holotype of junior synonym Olkenbachia hirsuta Solle, 1938 from the Devonian near Koblenz, Germany, reproduced from Solle (1938: fig. 2). E–F. Overview and SEM close-up of one of the paratypes of junior synonym Olkenbachia hirsuta (compare with Solle 1938: fig. 4).

Fig. 6. Clionolithes palmatus Clarke, 1908. A. Original drawing of the lectotype, a natural cast in a shell of Loxopteria dispar Sandberger & Sandberger, 1857 from the Upper Devonian of New York State, USA (reproduced from Clarke 1908: pl. 12, fig. 1). B. The lectotype in its present state, either slightly damaged or originally idealised. C. Original drawing of the paralectotype, a natural cast in a Loxonema danai Clarke, 1904 from the type locality (reproduced from Clarke 1908: pl. 12, fig. 2). D. Significantly damaged paralectotype. E–F. A number of natural casts in a shell of Leptostrophia Hall & Clarke, 1892 from the Devonian of Victoria, Australia, including the holotype (close-up in F) and several paratypes of junior synonym Clionolithes sollei Talent, 1963 (compare with Talent 1963: pl. 9, figs 3–8). G. SEM of a specimen cast in epoxy resin by Plewes (1996) from the Devonian of Iowa, USA, illustrating the morphological range within one trace, comprising sheet-like fans and galleries terminating in fine ramifications (reproduced from Plewes 1996: pl. 1, fig. 1).

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. 8. Clionolithes cervicornis (Vogel, Golubic & Brett, 1987). A. SEM of pyritised and epoxycast holotype in a Devonian brachiopod shell from New York State, USA. B–C. SEM overview and close-up of another specimen from the original material of Vogel et al., recorded in a coral substrate. D–E. Overview and close-up of several natural casts that are part of the suite of paratypes of Olkenbachia hirsuta Solle, 1938 (junior synonym of Clionolithes radicans Clarke, 1908), from the Devonian near Koblenz, Germany (compare with Solle 1938: fig. 5). F. Holotype of nomen nudum “Chondrites” symmetricus (Solle 1938), a morphologically similar (cf.) but unusually large specimen from the Devonian near Koblenz, Germany.