Taming an ichnotaxonomical Pandora’s box: revision of dendritic and rosetted microborings (ichnofamily: Dendrinidae)
Author
Wisshak, Max
text
European Journal of Taxonomy
2017
2017-12-29
390
1
99
journal article
21907
10.5852/ejt.2017.390
54438cfa-5f3a-4ee3-85c8-00e453a6d641
2118-9773
3839858
4D1D1CA3-8345-4BA3-9C7C-5EBDD40752CE
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
.