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Renidinium membraniferum
Renidinium membraniferum Morgenroth, 1968
Holotype: Morgenroth, 1968, pl.47, fig.1
Age: Danian
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Original description: [Morgenroth, 1968]:
Derivation of name: membraniferum, Latin: carrying a membrane.
Type location: Kjölby Gaard, Hunstrup NW Thisted (Denmark)
Type stratum: Danian A
Diagnosis (complement to the diagnosis of the genus):
the surface of the theca is slightly granulated. A thin-walled, unstructured outer membrane, completely free of processes, clings rather closely to the dorsal side. The distance between the theca and the outer membrane increases on the ventral side so that on both sides of the longitudinal groove "welts" are formed, which proceed in meridional direction. The longitudinal zone extends from the apex to the antapex, neither of which show any marked zoning (see Plate 46, Fig. 9). The zoning on the dorsal side is caused by smooth connecting ribs between the theca and the outer membrane (in contrast to the granulated surface). The transverse groove, only slightly depressed, is usually recognizeable only on the dorsal side. It proceeds approximately in equatorial direction. The outer covering, interrupted only above the longitudinal groove, terminates on the apex in one, on the antapex usually in two points; it can, however, also surround the antapex like a sack.
Measurements:
Length of the theca: 59 μ (47 μ/73 μ)
Width of the theca: 56 (45 μ/70 μ)
Height of the membrane welts: 5-14 μ (150 measurements)
Number of specimens examined: 2100.
Comparison: on superficial examination, the new species can be mistaken for Chiropteridium aspinatum (Gerlach 1961). It differs, however, from the latter species by the features described above.
Holotype: Morgenroth, 1968, pl.47, fig.1
Age: Danian
-------------------------------------------------------------------------------------------------------------------------------
Original description: [Morgenroth, 1968]:
Derivation of name: membraniferum, Latin: carrying a membrane.
Type location: Kjölby Gaard, Hunstrup NW Thisted (Denmark)
Type stratum: Danian A
Diagnosis (complement to the diagnosis of the genus):
the surface of the theca is slightly granulated. A thin-walled, unstructured outer membrane, completely free of processes, clings rather closely to the dorsal side. The distance between the theca and the outer membrane increases on the ventral side so that on both sides of the longitudinal groove "welts" are formed, which proceed in meridional direction. The longitudinal zone extends from the apex to the antapex, neither of which show any marked zoning (see Plate 46, Fig. 9). The zoning on the dorsal side is caused by smooth connecting ribs between the theca and the outer membrane (in contrast to the granulated surface). The transverse groove, only slightly depressed, is usually recognizeable only on the dorsal side. It proceeds approximately in equatorial direction. The outer covering, interrupted only above the longitudinal groove, terminates on the apex in one, on the antapex usually in two points; it can, however, also surround the antapex like a sack.
Measurements:
Length of the theca: 59 μ (47 μ/73 μ)
Width of the theca: 56 (45 μ/70 μ)
Height of the membrane welts: 5-14 μ (150 measurements)
Number of specimens examined: 2100.
Comparison: on superficial examination, the new species can be mistaken for Chiropteridium aspinatum (Gerlach 1961). It differs, however, from the latter species by the features described above.