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Epiplosphaera bireticulata
Epiplosphaera bireticulata *bireticulata Klement, 1960, p.74-75, pl.8, figs.1-4.
Taxonomic junior synonym: Palaeoperidinium (now Epiplosphaera) reticulatum, by implication in Courtinat (1989, p.176), who believed Palaeoperidinium (as Epiplosphaera) reticulatum to be the senior name - however, Poulsen (1992a, p.66) retained the two species.
Holotype: Klement, 1960, pl.8, figs.1-2; Fauconnier and Masure, 2004, pl.27, figs.2-5.
Age: Early Kimmeridgian.
Holotype: Klement, 1960, pl.8, figs.1-2
Locus typicus: Borehole Scherstetten 1, West Germany
Stratum typicum: Malm Gamma 3 (Similis-beds), Kimmeridgian
Age: Early Kimmeridgian
Translation Klement 1960: GSC
Original diagnosis: Klement 1960, p. 74: Epiplosphaera bireticulata
Typical species of the genus Epiplosphaera, characterized by an ellipsoidal central shell with fien, irregular polygonal, small-meshed basal network and by a superimposed larger-meshed sutural network, displating nonuniform individual meshes. This sutural network is formed through membranous connecting sutures whcih are of average breadth, stand perpendicular to the shell surface and, in a concave manner, hang between the short, apparently hollow processes which, distally, either terminate in a sharp point or branch out into short furcations.
Original description: Klement 1960, p. 74: Epiplosphaera bireticulata
The present species embodies a relatively unusual and therefore rather striking form type; it is for this reason that despite the few specimens at our disposal (which were found to be extremely well preserved in three-dimensional state), we were still able to clearly define the present species and to precisely separate it from forms which come close to it.
The mesh width of the extremely fine, irregular polygonal basic network (which is developed in form of a membranous reticualtion) fluctuates between 1 and 4.5 microns. Due to its extremely fine structure, the besic network can easily be oevelooked on superficial observation; however, when subjected to amore subtle examination, best done with the aid of a blue filter, thsi structure can be clearly discerned, at least in certain places. This basic structure is superimposed by a second, likewise irregular polygonal network strucutre, which possesses by far greater meshes which, in turn, are much less uniform; this superimposed network strucure consists of low, membranous sutural connections between the individual processes. These processes are of simple form, they are relatively short and appear tobe hollow on the inside, distally terminating into members which are either in form of two short lobular elements or in form of spines. The interconnecting sutures between said processes pull themselves up along the processes in each case, whereas they hang in a concave manner between two adjacent processes. These interconnecting sutures are extremely thin-walled, in part they are bent in an undualr manner, and their widths are of different orders of magnitude. Due to the delicate structure of these sutures, we can observe partial breakdowns of the mesh-like strucutres they had helped build.
In all specimens, one pole of the shell was split-off in each case in a calcotte-like manner, a criterium which -- due to the degree of regularity with whcih it occurs -- must be interpreted as pylome formation.
In addition to the customary lateral position of the organisms in the preparation, we could also observe in part an apex/antapex orientation, which allowed one to recognize a completely circular cross-section of the shell.
The membrane of the shell, in similar manner as the superimposed mambranous sutures,is present in a brownish-yellowish coloration.
Relationships: Klement 1960, p. 74
The criteria of the overall structural plan which are of a socalled differential-diagnostic nature, had been discussed already before when the genus was discussed (note: see the genus description).
The E. bireticualta can be precisely separated from the E. reticulospinosa n.sp. by the fact that, in the latter, a closed mesh network of the interconnecting sutures is missing. Likewise, a considerable difference exists with respect to the species E. areolata n.sp., namely in the arrangement and form of the superimposed network, which is built up solely in form of low bulge-like proturberances in the E.areolata, and is of a much more uniform design there.
However, the representative of the present genus which is classified here as Epiplosphaera sp., shows a similar habitus. It should be pointed out, however, that in the case of the latter, we were not able to observe the fine-meshed network on the shell surface, and that moreover, the superimposed mesh-like strucutre was more uniform and of a more cyclic form.
Taxonomic junior synonym: Palaeoperidinium (now Epiplosphaera) reticulatum, by implication in Courtinat (1989, p.176), who believed Palaeoperidinium (as Epiplosphaera) reticulatum to be the senior name - however, Poulsen (1992a, p.66) retained the two species.
Holotype: Klement, 1960, pl.8, figs.1-2; Fauconnier and Masure, 2004, pl.27, figs.2-5.
Age: Early Kimmeridgian.
Holotype: Klement, 1960, pl.8, figs.1-2
Locus typicus: Borehole Scherstetten 1, West Germany
Stratum typicum: Malm Gamma 3 (Similis-beds), Kimmeridgian
Age: Early Kimmeridgian
Translation Klement 1960: GSC
Original diagnosis: Klement 1960, p. 74: Epiplosphaera bireticulata
Typical species of the genus Epiplosphaera, characterized by an ellipsoidal central shell with fien, irregular polygonal, small-meshed basal network and by a superimposed larger-meshed sutural network, displating nonuniform individual meshes. This sutural network is formed through membranous connecting sutures whcih are of average breadth, stand perpendicular to the shell surface and, in a concave manner, hang between the short, apparently hollow processes which, distally, either terminate in a sharp point or branch out into short furcations.
Original description: Klement 1960, p. 74: Epiplosphaera bireticulata
The present species embodies a relatively unusual and therefore rather striking form type; it is for this reason that despite the few specimens at our disposal (which were found to be extremely well preserved in three-dimensional state), we were still able to clearly define the present species and to precisely separate it from forms which come close to it.
The mesh width of the extremely fine, irregular polygonal basic network (which is developed in form of a membranous reticualtion) fluctuates between 1 and 4.5 microns. Due to its extremely fine structure, the besic network can easily be oevelooked on superficial observation; however, when subjected to amore subtle examination, best done with the aid of a blue filter, thsi structure can be clearly discerned, at least in certain places. This basic structure is superimposed by a second, likewise irregular polygonal network strucutre, which possesses by far greater meshes which, in turn, are much less uniform; this superimposed network strucure consists of low, membranous sutural connections between the individual processes. These processes are of simple form, they are relatively short and appear tobe hollow on the inside, distally terminating into members which are either in form of two short lobular elements or in form of spines. The interconnecting sutures between said processes pull themselves up along the processes in each case, whereas they hang in a concave manner between two adjacent processes. These interconnecting sutures are extremely thin-walled, in part they are bent in an undualr manner, and their widths are of different orders of magnitude. Due to the delicate structure of these sutures, we can observe partial breakdowns of the mesh-like strucutres they had helped build.
In all specimens, one pole of the shell was split-off in each case in a calcotte-like manner, a criterium which -- due to the degree of regularity with whcih it occurs -- must be interpreted as pylome formation.
In addition to the customary lateral position of the organisms in the preparation, we could also observe in part an apex/antapex orientation, which allowed one to recognize a completely circular cross-section of the shell.
The membrane of the shell, in similar manner as the superimposed mambranous sutures,is present in a brownish-yellowish coloration.
Relationships: Klement 1960, p. 74
The criteria of the overall structural plan which are of a socalled differential-diagnostic nature, had been discussed already before when the genus was discussed (note: see the genus description).
The E. bireticualta can be precisely separated from the E. reticulospinosa n.sp. by the fact that, in the latter, a closed mesh network of the interconnecting sutures is missing. Likewise, a considerable difference exists with respect to the species E. areolata n.sp., namely in the arrangement and form of the superimposed network, which is built up solely in form of low bulge-like proturberances in the E.areolata, and is of a much more uniform design there.
However, the representative of the present genus which is classified here as Epiplosphaera sp., shows a similar habitus. It should be pointed out, however, that in the case of the latter, we were not able to observe the fine-meshed network on the shell surface, and that moreover, the superimposed mesh-like strucutre was more uniform and of a more cyclic form.