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Danea mutabilis
Danea mutabilis Morgenroth, 1968
Taxonomic senior synonym: Palmnickia (as Danea) californica, according to Damassa (1979b, p.193). The nomenclatural type of the genus Danea remains the holotype of Danea mutabilis.
Holotype: Morgenroth, 1968, pl.43, figs.5-6
Age: Danian
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Original description: [Morgenroth, 1968]:
Danea mutabilis n. sp.
Derivation of name: mutabilis, Lat.: variable, unstable.
Type locality: Katharinenhof (Danian block)
Type stratum: Danian.
Because or existing variability , the diagnosis must be preceded by an extensive description.
Description: the egg-shaped theca shows an outer layer of fibrous structure from which appendages rise. The apical pole, accented by a small polar protrusion of the theca, is marked in the majority of specimens by a long spine of fibrous structure. The flat, fibrous and distally usually
smooth-edged seams (height as a rule 11-28u) are concentrated in "zones" (compare Plate 43, Figs. 5-7) surrounded by wide uncovered bands. These "zones" are arranged in all specimens in the same manner. The seams can snow all transitions from distinct formation to faint traces within the variation range of the material available (compare Plate 43, Figs. 5-9). With increasing shortening of the seams, the basal contours of the "zones" crowd each other more and more (see Plate 3, Fis 7-9) so that the uncovered, separating bands becone correspondingly narrower until finally only seams remain. If we consider in such specimens the position of the "zones" on the theca, a schematic of plate arrangement can be recognized which can hardly be cistinguisned from some species of, for instance, the genus Gonyaulacysta. These findings are particularly distinct in some of 67 "extreme forms" in which the seams are entirely absent, with simultaneous thickening of the theca wall to 4-8 (!) u (see Plate 44, fig. 2). These specimens have a rather shallow girdle groove which spirals counterclockwise and a short, single-pointed apical spine, often also an antapical spine. In some, traces of a true plate formation can be reconized (see Plate 44, Fig. 3 ). In this species therefore, the Dinoflagellata characteristics are apparent in varying strength within the limits of the variation range. In most specimens, the formation of plates can be recognized only by the arrangement of the processes, which delineates the outline of the plates at a certain distance from the border of the plates (the true limits of the plates are also made obvious in "normal specimens" by the archaeopyle seam which runs approximately in the middle between the zones of the processes (see Plate 43, Fig. 7 !). The following schematic of plate arrangement results: the apex is marked by 4 apical plates of which plate 1' is located in the extension of the longitudinal groove; the trapezoidal plates 2' and 3', however, lie symmetrically above 3". 4' is located above the small elongated 6". Below the 4 apical platas, 6 pre-equatorial plates follow
on the epitheca; all but plate 6 are of trapezoidal form. The transverse groove, usually bisected by a band of processes proceeding centrally, spirals counterclockwise. Below, on the hypotheca, 6 post-equatorial plates are located of which the oblong plate 1'" is very degenerate. The triangular plates 2"' and 6'" are also very degenerate. 3'", 4"' and 5"' have a trapezohedral shape. An intercalary plate is definitely present. Another seems to be located on the other side of the longitudinal groove. The antapex is formed by one antapical plate. The archaeopyle is formed by separation of plate 3".
Diagnosis (complement to the diagnosis of the genus) :
a species of the genus Danea with an egg-shaped theca. The appendages are fibrous and of flat shape. Schematic of plate arrangement: 4', 6", 6"', ?2π, 1"". The apex is marked by a spine. In most cases, the theca reaches with small protrusions into the apical process. The transverse groove spirals slightly countorclockwise. The longitudinal groove widens slightly on the hypotheca.
The appendages can be suppress ed coıpletely except for 2 low, pointed spines on the apex and the antapex. In this case, however, a shallow transverse groove remains. The degeneration of the appendages is coupled with a tendency to considerable thickening of the theca wall.
Measurements:
Length of theca: 80 μ (64 μ/92 μ)
Width of theca: 68 μ (53 μ/78 μ)
Length of appendages: 0-28 μ
Length of apical spine: 5-42 μ (150 measurements)
Number of specimens examined: 475
Comparison:
The species mutabilis somewhat resembles Lanternosphaeridium radiatum Morgenroth 1966. When re-examining the original material however, a zone arrangement of the processes (which are shaped differently!) could not be detected.
Taxonomic senior synonym: Palmnickia (as Danea) californica, according to Damassa (1979b, p.193). The nomenclatural type of the genus Danea remains the holotype of Danea mutabilis.
Holotype: Morgenroth, 1968, pl.43, figs.5-6
Age: Danian
--------------------------------------------------------------------------------------------------------------------
Original description: [Morgenroth, 1968]:
Danea mutabilis n. sp.
Derivation of name: mutabilis, Lat.: variable, unstable.
Type locality: Katharinenhof (Danian block)
Type stratum: Danian.
Because or existing variability , the diagnosis must be preceded by an extensive description.
Description: the egg-shaped theca shows an outer layer of fibrous structure from which appendages rise. The apical pole, accented by a small polar protrusion of the theca, is marked in the majority of specimens by a long spine of fibrous structure. The flat, fibrous and distally usually
smooth-edged seams (height as a rule 11-28u) are concentrated in "zones" (compare Plate 43, Figs. 5-7) surrounded by wide uncovered bands. These "zones" are arranged in all specimens in the same manner. The seams can snow all transitions from distinct formation to faint traces within the variation range of the material available (compare Plate 43, Figs. 5-9). With increasing shortening of the seams, the basal contours of the "zones" crowd each other more and more (see Plate 3, Fis 7-9) so that the uncovered, separating bands becone correspondingly narrower until finally only seams remain. If we consider in such specimens the position of the "zones" on the theca, a schematic of plate arrangement can be recognized which can hardly be cistinguisned from some species of, for instance, the genus Gonyaulacysta. These findings are particularly distinct in some of 67 "extreme forms" in which the seams are entirely absent, with simultaneous thickening of the theca wall to 4-8 (!) u (see Plate 44, fig. 2). These specimens have a rather shallow girdle groove which spirals counterclockwise and a short, single-pointed apical spine, often also an antapical spine. In some, traces of a true plate formation can be reconized (see Plate 44, Fig. 3 ). In this species therefore, the Dinoflagellata characteristics are apparent in varying strength within the limits of the variation range. In most specimens, the formation of plates can be recognized only by the arrangement of the processes, which delineates the outline of the plates at a certain distance from the border of the plates (the true limits of the plates are also made obvious in "normal specimens" by the archaeopyle seam which runs approximately in the middle between the zones of the processes (see Plate 43, Fig. 7 !). The following schematic of plate arrangement results: the apex is marked by 4 apical plates of which plate 1' is located in the extension of the longitudinal groove; the trapezoidal plates 2' and 3', however, lie symmetrically above 3". 4' is located above the small elongated 6". Below the 4 apical platas, 6 pre-equatorial plates follow
on the epitheca; all but plate 6 are of trapezoidal form. The transverse groove, usually bisected by a band of processes proceeding centrally, spirals counterclockwise. Below, on the hypotheca, 6 post-equatorial plates are located of which the oblong plate 1'" is very degenerate. The triangular plates 2"' and 6'" are also very degenerate. 3'", 4"' and 5"' have a trapezohedral shape. An intercalary plate is definitely present. Another seems to be located on the other side of the longitudinal groove. The antapex is formed by one antapical plate. The archaeopyle is formed by separation of plate 3".
Diagnosis (complement to the diagnosis of the genus) :
a species of the genus Danea with an egg-shaped theca. The appendages are fibrous and of flat shape. Schematic of plate arrangement: 4', 6", 6"', ?2π, 1"". The apex is marked by a spine. In most cases, the theca reaches with small protrusions into the apical process. The transverse groove spirals slightly countorclockwise. The longitudinal groove widens slightly on the hypotheca.
The appendages can be suppress ed coıpletely except for 2 low, pointed spines on the apex and the antapex. In this case, however, a shallow transverse groove remains. The degeneration of the appendages is coupled with a tendency to considerable thickening of the theca wall.
Measurements:
Length of theca: 80 μ (64 μ/92 μ)
Width of theca: 68 μ (53 μ/78 μ)
Length of appendages: 0-28 μ
Length of apical spine: 5-42 μ (150 measurements)
Number of specimens examined: 475
Comparison:
The species mutabilis somewhat resembles Lanternosphaeridium radiatum Morgenroth 1966. When re-examining the original material however, a zone arrangement of the processes (which are shaped differently!) could not be detected.