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Chiropteridium lobospinosum

Chiropteridium lobospinosum, (Gocht in Weiler, 1956), Gocht, 1960

Originally Hystrichosphaeridium, subsequently (and now) Chiropteridium; see also Baltisphaeridium (combination not validly published).
Eisenack and Kjellstrom, 1971, p.161) gave the citation Chiropteridium lobospinosum Gocht, 1960, and cited the holotype as the specimen illustrated in Gocht, 1960, pl.17, fig.1. However, Gocht in Weiler, 1956, met all the criteria at that time for valid publication of this species.

Holotype: not designated
Lectotype: Weiler, 1956, pl.12, fig.3; designated by Lentin and Williams, 1989
Locus typicus: Werrabronn12 Borehole, Germany
Stratum typicum: Middle Oligocene

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Gocht, 1960, p. 222: (Translation: LPP):

Diagnosis:
Main body roundish to oval, at the antapex often flattened. Middle surfaces always free; processes only in the marginal zone, more or less clearly arranged in 2 annular rows, which may be located in different plains, and which may dissolve at the polar regions. Generally 4 antapical processes, often slender and tubular, more seldom planar and broad; distally divided. Apical process elongate, hose-shaped, distally blunt, widened, rarely pointed. Interpolar processes mostly planar, partially forming narrower strips, partially broad, more or less partitioned patches; distal ends, by indentations of varying depth, mostly dissolved into processes, which often, as if cut off, in a plateau.

Dimensions:
holotype: 102:91 µm. Total length 169 µm, total breadth 141 µm. Largest length of other specimens 127-218 µm (mostly between 155 and 172 µm (240 specimens).

Affinities: (p. 228):
Chiropteridium dispersum differs from C. lobospinosum in the smaller size, in irregular, subdivided planar processes and small, narrow to pointed appendages, which also extend to the middle areas. The polar processes are less well distinguished.

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Description as "morphotype D":

Schindler, 1992, p. 206: (Translation: GSC, courtesy R. Fensome):

Description:
Cyst two-layered. The globose endocyst is flattened dorsoventrally and between the antapical processes, and completely enclosed by the periphragm. The detachment boundaries of the two phragmas have vertical oval outlines ventrally and dorsally, so that they can not be used for orientation in this case. Starting from the detachment boundaries, the periphragm forms four meridional lateral fimbriae on the dorsal and ventral faces. The proximal margin of these fimbriae is free of notches and may be gently undulate. The shape of the distal margin varies considerably. It is divided by horseshoe-shaped arches of different sizes - which only seldom reach deeper than to the middle of the fimbria - into fimbriate segments of different lengths. The segments between arches are frequently distally denticulate or notched, or produced into fine processes (fig. 7 and 8), and end at different heights. At the apical end, the fimbriae terminate just below the archeopyle margin, so that even with the archeopyle closed, the lateral fimbriae have no contact, at least proximally, with the apical fimbria on the operculum. This apical fimbria is lobulate, bifid, and distally blunt or notched and drawn out into fine processes. Approximately at the middle of the operculum there is a cylindrical, usually distally truncate, dominant apical process (fig. 7b). The antapical processes either are separated from the lateral fimbriae by deep, arcuate incisions, or simply form their antapical extension. This is frequently observed on the dorsal side. Also, the processes on the dorsal side are generally somewhat shorter and not strongly expressed. The antapical processes are usually planar (fig. 8b), only seldom tubular. They are frequently lightly constricted at the middle. Distally they tend to split into outgrowths of different lengths and widths. Also in this form, the archeopyle exhibits the characteristic zigzag suture. Dorsally there is a notch of medium depth at the middle. The ventral side is characterized by an acute to rounded notch on the right and the parasulcal notch offset to the left. The region in between is acute or applanate (fig. 8a). Once again, the surface of the periphragm is granulate where it is in contact with the endophragm and distinctly smoother-on fimbriae and processes. In this form, recesses in the periphragm are more likely to occur individually and on the left of the ventral side.

Measurements:
entire cyst:length: 102-147 µm breadth: 79-138 µm
endocyst:length: 58-93 µm breadth: 47-90 µm

Affinities/Comparison:
The arches dividing the lateral fimbriae are especially characteristic of Morphotype D, which differs in this character from all the other morphotypes (A, B, C, and E). The presence of four antapical processes further differentiates it from Chiropteridium aspinatum (Morphotype A) and C. brevifolium (Morphotype C), as well as from Morphotype B. Morphotype D can definitely be classified as the species Chiropteridium lobospinosum. The only differences are the greater body measurements of the type material of Chiropteridium lobospinosum and the wider range of variation in my material with respect to size.
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