Back
Histiophora ornata
Histiophora ornata Klement, 1960, p.51-53
Holotype: Klement, 1960, pl.6, figs.11–13; Fauconnier and Masure, 2004, pl.37, figs.12–13.
Locus typicus: Borehole Scherstetten 1
Stratum typicum: Malm Lower-Delta; cores samples removed from region between 1,682.3 and 1,683.6 meters.
Age: Late Jurassic
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Histiophora ornata Klement, 1960, has distally denticulate crests with radial thickenings. Size: length 46-72 µm, width 35-52 µm
--------------------------------------------------
Translation Klement 1960: GSC
Original diagnosis: Klement 1960, p. 51, Hystiosphaera ornata
Typical species of the genus Histiophora with the following arrangement of the trapezium-shaped areolas (fields) which are bordered by hyaline seams which, distally, are finely denticualted: the epitheca and the hypotheca are covered with 4 fields each dorsally and marginally, slightly extending over to the ventral side. Of these areolas (fields) we find two each in the middle of the section of both epi- and hypovalva. Two additionalepithecal fields of analogous form and size lie mraginally, sligthly extending over to the ventral side. On the hypothecal side we find another similar areola whcih lies marginally and extends in ventral direction; a reduces, trapezoidal field with reduced border-seams lies likewise ventrally.The remaining protion of the ventral side of the envelope is taken up by areolas which are not closed-off by seams, but are ornamented with a few, low, undular lists which extend in longitudinal and transversal direction.
Apical pole-cap is smooth dorsally, and broadly denticulated ventrally; it forms the pylome. Antapex is covered with a trapezium-shaped areoal whcih is bordered by seams and is slightly extending over to the ventral side.
Seams which form the borders of the fields are thin and hyaline, however, relatively stiff; distally finely denticulated, these seams, in part, display slightly elongated, spiny protuberances, which continue in form of intermembranously thickened strut-like members extending to the seam base.
Description: Klement 1960, p. 51, Hystiosphaera ornata
This species -- which was documented by numerous specimens which, for the major portion, were found in a completely three-dimensional state-- is extremely conspicious due to its unusually ornamented armor. In characteristic manner, the ellipsoidal envelope shows, dorally and slightly over to the ventral side, a differentiation into trapezium-shaped areolas (fields), which are isoalted from one another though intermediary strips and are bordered by broad, denticulated seams and, moreover, are arranged in an orriented manner around a girdle zone which is free of any fields. However, with the exception of the 4th hypothecal field, there exists no closed-off areola on the ventral side, and we find solely afew low lists of varying lengths, which extend in longitudinal and transversal direction.
In all representatives, the apical pole-cap was torn-off in analogous manner and, ventrally, displays a broadly denticulated tear line in contrast to the smooth dorsal tear line. The opening, which has been created in this manner, is interpreted as pylome and its location is used as orientation criterium for the armor.
The antapex bears a trapezium-shaped field which, in analogous manner to the border of the dorsal areolas (fields), is likewise bordered by denticulated seam lists. All specimens had the following criterium in common, namely a displacement of the antapical field from the geometric pole of the ellipsoid in slanted direction toward the ventral side and more specifically in the direction toward the 4th hypothecal field.
A field-free girdle zone, of apparently slight helicoidal course, can be noticed especially on the dorsal side and extends on both sides slightly over to the ventral side, wtihout that a furrow-like depression could be ascertained. Likewise, we can not see that a longitudinal furrow had developed.
The seams forming the borders of the dorsal fields become quite broad at times (attaining breadth ranging between 6 and 10 microns). Distally, these seams range from being finely denticulated to terminating into slightly elongated , spiny proturberances which, as intermembranously thickened strut-like members, can be followed up to the base of the seam. The membrane of the seams appears to be very thin and, for this reason, is definetely hyaline; however, it proves to be relatively stiff.
The completely smooth and non-differantiated membrane of the envelope has a light yellow coloration.
A slight variation of the external habitus limits itself to the different breadths of the seams, as well as to the presence of a more or less thick-set contour of the ellipsoidal envelope.
Holotype: Klement, 1960, pl.6, figs.11–13; Fauconnier and Masure, 2004, pl.37, figs.12–13.
Locus typicus: Borehole Scherstetten 1
Stratum typicum: Malm Lower-Delta; cores samples removed from region between 1,682.3 and 1,683.6 meters.
Age: Late Jurassic
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Histiophora ornata Klement, 1960, has distally denticulate crests with radial thickenings. Size: length 46-72 µm, width 35-52 µm
--------------------------------------------------
Translation Klement 1960: GSC
Original diagnosis: Klement 1960, p. 51, Hystiosphaera ornata
Typical species of the genus Histiophora with the following arrangement of the trapezium-shaped areolas (fields) which are bordered by hyaline seams which, distally, are finely denticualted: the epitheca and the hypotheca are covered with 4 fields each dorsally and marginally, slightly extending over to the ventral side. Of these areolas (fields) we find two each in the middle of the section of both epi- and hypovalva. Two additionalepithecal fields of analogous form and size lie mraginally, sligthly extending over to the ventral side. On the hypothecal side we find another similar areola whcih lies marginally and extends in ventral direction; a reduces, trapezoidal field with reduced border-seams lies likewise ventrally.The remaining protion of the ventral side of the envelope is taken up by areolas which are not closed-off by seams, but are ornamented with a few, low, undular lists which extend in longitudinal and transversal direction.
Apical pole-cap is smooth dorsally, and broadly denticulated ventrally; it forms the pylome. Antapex is covered with a trapezium-shaped areoal whcih is bordered by seams and is slightly extending over to the ventral side.
Seams which form the borders of the fields are thin and hyaline, however, relatively stiff; distally finely denticulated, these seams, in part, display slightly elongated, spiny protuberances, which continue in form of intermembranously thickened strut-like members extending to the seam base.
Description: Klement 1960, p. 51, Hystiosphaera ornata
This species -- which was documented by numerous specimens which, for the major portion, were found in a completely three-dimensional state-- is extremely conspicious due to its unusually ornamented armor. In characteristic manner, the ellipsoidal envelope shows, dorally and slightly over to the ventral side, a differentiation into trapezium-shaped areolas (fields), which are isoalted from one another though intermediary strips and are bordered by broad, denticulated seams and, moreover, are arranged in an orriented manner around a girdle zone which is free of any fields. However, with the exception of the 4th hypothecal field, there exists no closed-off areola on the ventral side, and we find solely afew low lists of varying lengths, which extend in longitudinal and transversal direction.
In all representatives, the apical pole-cap was torn-off in analogous manner and, ventrally, displays a broadly denticulated tear line in contrast to the smooth dorsal tear line. The opening, which has been created in this manner, is interpreted as pylome and its location is used as orientation criterium for the armor.
The antapex bears a trapezium-shaped field which, in analogous manner to the border of the dorsal areolas (fields), is likewise bordered by denticulated seam lists. All specimens had the following criterium in common, namely a displacement of the antapical field from the geometric pole of the ellipsoid in slanted direction toward the ventral side and more specifically in the direction toward the 4th hypothecal field.
A field-free girdle zone, of apparently slight helicoidal course, can be noticed especially on the dorsal side and extends on both sides slightly over to the ventral side, wtihout that a furrow-like depression could be ascertained. Likewise, we can not see that a longitudinal furrow had developed.
The seams forming the borders of the dorsal fields become quite broad at times (attaining breadth ranging between 6 and 10 microns). Distally, these seams range from being finely denticulated to terminating into slightly elongated , spiny proturberances which, as intermembranously thickened strut-like members, can be followed up to the base of the seam. The membrane of the seams appears to be very thin and, for this reason, is definetely hyaline; however, it proves to be relatively stiff.
The completely smooth and non-differantiated membrane of the envelope has a light yellow coloration.
A slight variation of the external habitus limits itself to the different breadths of the seams, as well as to the presence of a more or less thick-set contour of the ellipsoidal envelope.