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Hystrichosphaera dentata
Hystrichosphaera? dentata Gocht, 1959, p.75–76, pl.4, fig.11; pl.7, fig.19. Emendation: Duxbury, 1977, p.49–50, as Spiniferites dentatus.
NOW Spiniferites. Originally Hystrichosphaera?, subsequently Spiniferites?, thirdly (and now) Spiniferites. Gocht, 1959, questionably included this species in Hystrichosphaera.
Holotype: Gocht, 1959, pl.4, fig.11
Age: Late Hauterivian
Original diagnosis: Gocht 1959, p. 75: Hystrichosphaera?dentata
The body is slightly oval and tabulate. Dorsally, the median girdle furrow is made up of small fields of an approximately rhornbohedral shape. The field boundaries of the epi-, and hypovala are marked by sturdy crest-sutures which, distally, are resolved into processes which are flat and generally truncated. The epi-, and hypovalva consist probably of 5 central fields each and 1 polar field each. The central dorsal field of the epivalva is at times broken out (pylome).
Additional Remarks: Gocht 1959, p. 75
Of the 5 specimens, 2 are in a fairly good state of preservation, however, cysts - which had been compressed to a greater degree - allow one to recognize the species on the basis of the characteristic sutures. On the holotype, the girdle can be discerned quite well, however, only on the (dorsal) upper side. This girdle is sub-divided into several rhombohedral fields, which in turn are bordered by narrow lists. The lists bear individual sturdy processes. No sign of the girdle can be recognized on the ventral side. On the dorsal side, a (broken-out) trapezoidal field lies in the center of the epivalva It is bordered to the left and to the right by sutures, which extend from the girdle til almost to the poles. The sutures,which form the lateral margin, form the boundaries of two additional epivalva fields. As far as the hypotheca is concerned, the field boundaries extend in an approximately corresponding manner, only the fourth longitudinal suture can not be detected in this case. Also on the ventral side, only one segment of a suture is visible , and that only quite indistinctly. Another specimen (Plate 7, Figure 19) apparently has the ventral side facing in upurard direction. The equator is not bordered by lists here, but is solely indicated by two rows of processes. One longitudinal suture each extends in the center toward the poles, and the sutures of the 4 upper fields,which form the lateral margin, follow to the left and to the right . As far as the epivalva is concerned, the two sutures of the central field of the bottom side (central dorsal field?) can be seen as well. Thus, the provisional combination of the two specimens furnishes 5 trapezoidal epitheca fields and 5 - possibly only 4 - hypotheca fields. That polar fields also exist in addition to the aforementioned fieds, as apparent from the arrangements of the sutures at the poles. Continuous longitudinal fields, which interrupt the girdle, could not be observed. The crest-like sutures are a unit by themselves, that is to say, they are not provided with supporting elements.Their processes are formed through more or less uniform rounded protuberances of the sutures which extend down to the lower third portion.On top, the processes are truncated in a straight line, occasionally they are also slightly retracted over the center portion. Whether the sutures are one-layered or whether they represent original bodily protuberances of the wall, has to remain unanswered for the time being. However, pyritic deposits and the shape of the isolated processes at girdle height , which had not united together to form sutures, might speak in favor of the last mentioned hypothesis. The sharpely delineated central oval shape might then correspond to an internal body. Since the course of the girdle is still a question mark, the species can be placed only with reservations to the Hystrichosphaera. Habitus and the rather sturdy, yellowish-brownish membrane could point to an association with the Dinoflagellates.
Dimensions: Holotype: Length 73 microns, breadth 70 microns. Central body 55:47 microns, breadth of the crest sutures 5-15 microns. Specimen shown in Plate 7, Figure 19: 78:70 microns. Other specimens have a length ranging from 57 to 85 microns.
Emended diagnosis: Duxbury, 1977, p. 49
A fairly thick-walled species of Spiniferites. The main body is spheroidal to ellipsoidal, longer than broad. The periphragm is produced into short, trifurcate gonal processes connected along body sutures by high crests. Along the sutural crests are evenly-spaced, broad-based sutural processes. These bifurcate at right angles to the crest length and may subsequently bifurcate again. The sutural process length varies considerably between specimens. Tabulation typical for the genus, archeopyle precingular, formed by loss of plate 3".
Observed dimensions: Overall 88(71)55x77(68)50 Ám.
NOW Spiniferites. Originally Hystrichosphaera?, subsequently Spiniferites?, thirdly (and now) Spiniferites. Gocht, 1959, questionably included this species in Hystrichosphaera.
Holotype: Gocht, 1959, pl.4, fig.11
Age: Late Hauterivian
Original diagnosis: Gocht 1959, p. 75: Hystrichosphaera?dentata
The body is slightly oval and tabulate. Dorsally, the median girdle furrow is made up of small fields of an approximately rhornbohedral shape. The field boundaries of the epi-, and hypovala are marked by sturdy crest-sutures which, distally, are resolved into processes which are flat and generally truncated. The epi-, and hypovalva consist probably of 5 central fields each and 1 polar field each. The central dorsal field of the epivalva is at times broken out (pylome).
Additional Remarks: Gocht 1959, p. 75
Of the 5 specimens, 2 are in a fairly good state of preservation, however, cysts - which had been compressed to a greater degree - allow one to recognize the species on the basis of the characteristic sutures. On the holotype, the girdle can be discerned quite well, however, only on the (dorsal) upper side. This girdle is sub-divided into several rhombohedral fields, which in turn are bordered by narrow lists. The lists bear individual sturdy processes. No sign of the girdle can be recognized on the ventral side. On the dorsal side, a (broken-out) trapezoidal field lies in the center of the epivalva It is bordered to the left and to the right by sutures, which extend from the girdle til almost to the poles. The sutures,which form the lateral margin, form the boundaries of two additional epivalva fields. As far as the hypotheca is concerned, the field boundaries extend in an approximately corresponding manner, only the fourth longitudinal suture can not be detected in this case. Also on the ventral side, only one segment of a suture is visible , and that only quite indistinctly. Another specimen (Plate 7, Figure 19) apparently has the ventral side facing in upurard direction. The equator is not bordered by lists here, but is solely indicated by two rows of processes. One longitudinal suture each extends in the center toward the poles, and the sutures of the 4 upper fields,which form the lateral margin, follow to the left and to the right . As far as the epivalva is concerned, the two sutures of the central field of the bottom side (central dorsal field?) can be seen as well. Thus, the provisional combination of the two specimens furnishes 5 trapezoidal epitheca fields and 5 - possibly only 4 - hypotheca fields. That polar fields also exist in addition to the aforementioned fieds, as apparent from the arrangements of the sutures at the poles. Continuous longitudinal fields, which interrupt the girdle, could not be observed. The crest-like sutures are a unit by themselves, that is to say, they are not provided with supporting elements.Their processes are formed through more or less uniform rounded protuberances of the sutures which extend down to the lower third portion.On top, the processes are truncated in a straight line, occasionally they are also slightly retracted over the center portion. Whether the sutures are one-layered or whether they represent original bodily protuberances of the wall, has to remain unanswered for the time being. However, pyritic deposits and the shape of the isolated processes at girdle height , which had not united together to form sutures, might speak in favor of the last mentioned hypothesis. The sharpely delineated central oval shape might then correspond to an internal body. Since the course of the girdle is still a question mark, the species can be placed only with reservations to the Hystrichosphaera. Habitus and the rather sturdy, yellowish-brownish membrane could point to an association with the Dinoflagellates.
Dimensions: Holotype: Length 73 microns, breadth 70 microns. Central body 55:47 microns, breadth of the crest sutures 5-15 microns. Specimen shown in Plate 7, Figure 19: 78:70 microns. Other specimens have a length ranging from 57 to 85 microns.
Emended diagnosis: Duxbury, 1977, p. 49
A fairly thick-walled species of Spiniferites. The main body is spheroidal to ellipsoidal, longer than broad. The periphragm is produced into short, trifurcate gonal processes connected along body sutures by high crests. Along the sutural crests are evenly-spaced, broad-based sutural processes. These bifurcate at right angles to the crest length and may subsequently bifurcate again. The sutural process length varies considerably between specimens. Tabulation typical for the genus, archeopyle precingular, formed by loss of plate 3".
Observed dimensions: Overall 88(71)55x77(68)50 Ám.