Calcideletrix breviramosa 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 : 38-39

Calcideletrix breviramosa Mägdefrau, 1937

Fig. 12

Calcideletrix breviramosa Mägdefrau, 1937: 58 , pl. IV, fig. 9.

Calcideletrix breviramosa – Häntzschel 1962: W228, fig. 142-5 (reproduced from Mägdefrau 1937); 1975: W124, fig. 77-4a (reproduced from Mägdefrau 1937). — Nadjin 1969: 138, pl. IV, fig. 9 (reproduced from Mägdefrau 1937). — (?) Marcinowski 1972: 247, pl. 2, fig. 2 (poor illustration).

Calcideletrix flexuosa – Ghare 1982: 132, pl. 1, fig. 5.

non Calcideletrix breviramosa – Ghare 1982: 132, pl. 1, fig. 6 (= Dictyoporus nodosus ). — (?) Košt’ák

2004: 32, fig. 12 (? Dictyoporus nodosus ).

Original diagnosis

n/a

Emended diagnosis

Extended system with mainly straight and partly bending or bifurcating main tunnel of constant diameter, from which numerous lateral secondary tunnels of same diameter emerge and taper or connect to the substrate surface. No true anastomosis and only little widening at branching points.

Original description

Distinctly structured in main and secondary branches, both of same diameter (0.02–0.04 mm). The secondary branches mostly diverge at an angle of 60° from the main channel and almost all penetrate the surface of the belemnite rostrum, similar to Talpina ramosa . [Translated from German]

Type material, locality and horizon

Holotype ( Fig. 12 A–C) preserved in rostrum of an Actinocamax Miller, 1826 (belemnite) from the Upper Cretaceous of Misburg near Hannover , Germany, deposited in the collections of the Institut für Geowissenschaften und Geographie, Halle, Germany ( MLU.Mäg1937.IV.9 ).

Remarks

Due to the lack of a defined centre or point of entry, this ichnospecies is rather an extended tunnel system than a dendrinid trace and represents a morphological end member of Calcideletrix . This feature and the relatively constant diameter of the main and secondary branches distinguish C. breviramosa from the other ichnospecies of Calcideletrix .

Figures

Fig. 12. Calcideletrix breviramosa Mägdefrau, 1937. A–C. Holotype covering several square centimetres of an Upper Cretaceous belemnite from Misburg, Germany. Close-up in B shows main tunnels with lateral secondary galleries and close-up in C illustrates connections to the substrate surface at the end of the secondary branches (arrows).