Calcideletrix flexuosa Mägdefrau, 1937

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 : 36-38

Calcideletrix flexuosa Mägdefrau, 1937

Fig. 11

Calcideletrix flexuosa Mägdefrau, 1937: 57 , pl. IV, fig. 4.

Dendrina brachiopodicola Hofmann, 1996: 80 , pl. 9, figs 1–4 .

Clionolithes radicans – Clarke 1908 (partim): 168, pl. 10, pl. 11, fig. 2; 1921 (partim): 88, fig. 71 (drawing based on photograph in Clarke 1908).

Calcideletrix flexuosa – Häntzschel 1962: W228, fig. 142-4 (reproduced from Mägdefrau 1937); 1975: W124, fig. 77-4b (reproduced from Mägdefrau 1937). — Pugaczewska 1965: 76, pl. I, fig. 3; (?) 1970: 428, pl. I, fig. 2, pl. II, fig. 2 (poor illustrations). — Nadjin 1969: 138, pl. IV, fig. 4 (reproduced from Mägdefrau 1937). — Plewes 1996 (partim): 188, pl. 31, figs 7–8, pl. 33, figs 1–7 , pl. 34, figs 1–4 (pl. 34, figs 5–6 = Dictyoporus nodosus ). — Buatois et al. 2017: 161, fig. 75B (holotype). — Wisshak et al. 2017: 131, figs 3/4, 4/4.

Rosetten-Form G – Hofmann & Vogel 1992: 57, pl. IV, fig. B.

Without name – Reich & Frenzel 2002 (partim): 208, pl. 50, fig. 7.

Calcideletrix – Whittlesea 2005: 18, fig. 3.

Dendrina anomala – Rudolph 2014 (partim): 19, fig. 24 (specimen on the left).

non Calcideletrix flexuosa – Ghare 1982: 132, pl. 1, fig. 5 (= Calcideletrix breviramosa ). — (?) Košt’ák

2004: 32, fig. 11 (? Dictyoporus nodosus ). — (?) Stiller 2005: 406, pl. II, figs 3, 15 (poor illustration).

Original diagnosis

n/a

Emended diagnosis

Highly ramified, with most branches remaining roughly the same width up to their tapering ends. Branches ramify in a relatively straight manner, although curves develop at irregular intervals. Branches

ramify in such a way as to cover the space between branches almost equally. Anastomosis is rare and restricted to the centre of the trace.

Original description

Channels strongly ramified, 0.04–0.09 mm in diameter. Only the main channel, at the basis of the shrub, opens to the surface, while the side channels do not penetrate to the surface of the belemnite rostrum. [Translated from German]

Supplementary description

Based on cast material, Plewes (1996) added the following observations: “Cast material shows that the profile of the branches is rounded and sometimes shows a hint of the bubbly texture reminiscent of, but not as pronounced as that seen in C. anomala . Width of the branches varies between 25 µm and 250 µm, with a mean of 98 µm (n = 18, SD = 50.08). Surface texture may also include hair-like filaments. These are between 1 µm and 2.5 µm in width and vary greatly in length. The loops which form as a result of anastomoses between branches within the main body of the trace vary in size and may enclose other blind ending branches. Branching angle varies greatly but is between 90° and 45°, and branching may be polychotomous or dichotomous. Nodes are sometimes swollen and form rounded irregular edges, especially if the branching point is not a simple dichotomy. The spacing between branches varies but is between 380 µm and 900 µm (n = 9, SD = 245.9).” Hofmann (1996) additionally gave a size range of the junior synonym D. brachiopodicola of 1.3 to 3.7 mm.

Type material, locality and horizon

Holotype ( Fig. 11 A–C) preserved in rostrum of Belemnitella mucronata from the Upper Cretaceous of Misburg near Hannover , Germany, deposited in the collection of the Institut für Geowissenschaften und Geographie, Halle, Germany ( MLU.Mäg1937.IV.4 ).

Remarks

Hofmann’s Dendrina brachiopodicola very closely resembles C. flexuosa in morphology and dimensions, and was established as a separate taxon based on its vertically oriented oval gallery cross section only. However, Mägdefrau did not specify the tunnel cross-section and this character alone does not justify its use as the ichnotaxobase for a separate ichnospecies, let alone an ichnospecies within a different ichnogenus, and it is thus regarded as a junior synonym herein.

Figures

Fig. 11. Calcideletrix flexuosa Mägdefrau, 1937. A–C. Holotype in an Upper Cretaceous belemnite rostrum from Misburg, Germany. Close-up in B illustrates anastomosis and two potential points of initial entry (arrows). Close-up in C shows peripheral ramification. D–F. Respective SEM views of an epoxy casts of the holotype of junior synonym D. brachiopodicola Hofmann, 1996, illustrating the very close morphological resemblance of the trace in a belemnite vs a brachiopod substrate. G. Natural casts in a Devonian brachiopod with several C. flexuosa (original of Clarke 1908: pl. 10; damaged since original publication). H. Another silicified cast in a Devonian brachiopod shell (reproduced from Clarke 1908: pl. 11, fig. 2).

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.