Back
Ovum hispidum subsp. bulbosum
Ovum hispidum subsp. bulbosum (Ehrenberg, 1837b, pl.1, fig.17) Downie and Sarjeant, 1965, p.174. Emendation: Morgenroth, 1968, p.546–547, as Hystrichokolpoma bulbosum.
Combination not validly published: specific name not validly published and combination not intended. NOW Hystrichokolpoma bulbosum. Originally Xanthidium bulbosum, subsequently Hystrichosphaera bulbosa (combination not validly published), thirdly Hystrichosphaeridium bulbosum, fourthly Ovum hispidum bulbosum (combination not validly published), fifthly (and now) Hystrichokolpoma bulbosum, sixthly Baltisphaeridium bulbosum (combination not validly published).
Taxonomic senior synonym: Xanthidium (as Hystrichosphaeridium) tubiferum, according to Stover and Evitt (1978, p.55) — however, Lentin and Williams (1981, p.134) retained Xanthidium (as Hystrichokolpoma) bulbosum.
Downie and Sarjeant (1965, p.174) gave the citation "O. [Ovum] hispidum bulbosum (Ehrenberg, 1838a [1837b herein]) Lohmann, 1904, now Hystrichosphaeridium." However, we have not been able to locate the combination Ovum hispidum subsp. bulbosum in Lohmann (1904).
Holotype: Ehrenberg, 1837b, pl.1, fig.17.
Neotype: Morgenroth, 1968, pl.44, fig.6, designated by Morgenroth (1968, p.546).
Age: Danian.
---------------------------------------------------------------------------------------------------------------------------------------------------
Emendation [Morgenroth, 1968] (translated from German):
After examining numerous specimens from the Danien (see below), it is essential to define the species by means of a clearly oriented neotype with recognizable species and genus characteristics (dorsal and ventral apical appendages). Since the arrangement of the processes cannot be reliably determined on the specimen illustrated by EHRENBERG (so that it is insufficient as a type!), a neotype is hereby established which occupies a central position within the range of variation of the species and exhibits all important characteristics. The specimen preserved in Prep. KG10 and illustrated on Pl. 44, Fig. 6 is selected as the neotype.
Type locality: Kjölby Gaard, Hunstrup NW Thisted (Denmark).
Type stratum: Danian A.
Diagnosis: A species of the genus Hystrichokolpoma with the following pattern of process arrangement: 6', 6", 7, 7"', 2π, ππλ, 1"". Theca globular to distinctly ellipsoid. Theca surface weakly granulated. Girdle left-spiraling.
Process structure: Usually relatively tall, slender, distally trumpet-shaped, structureless. The distal margin is usually toothed (= "tubiferum process type"!). The base contours of the processes are usually separated from each other on the theca by larger spaces.
Within the range of variation, the processes can broaden considerably at the base, so that their basal contours are only separated from each other by narrow strips (bulbosa-process type!). The broadening of the processes is regularly accompanied by a shortening.
Archeopyle: Splitting of the apical polar cap with 2'-6'.
Description: The surface of the weakly ellipsoidal to spherical theca is granulated. In the apex region are 6 apical processes, of which 1' lies in the extension of the longitudinal field and is somewhat elongated in its direction. The other 5 apical processes are shed with the apical polar cap during pylode formation (see Plate 44, Fig. 6). Towards the girdle follow 6 relatively broad processes, which are to be regarded as pracequatorial processes. The girdle is covered with 7 processes, of which 1-6 are elongated at the base in the direction of the girdle, with the exception of 7, which has a circular base Below the girdle are seven post-equatorial processes (1"' and 2"' are very slender with a narrow base, 3"'-6"' are relatively voluminous, and 7'" is again very slender). Two robust intercalary processes lie below 1'" and 7'". One process is located on the hypothecal part of the longitudinal field. The antapex is characterized by a robust antapical process. The arrangement of the processes can be seen in Figures 6 and 7 on Plate 44.
Dimensions:
Theca lengths: 34 μ (31 μ/43 μ)
Theca width: 30 μ (25 μ/33 μ)
Process length: approx. 14-22 μ (6 μ/31 μ)
(100 measurements)
Number of specimens examined: 750
Comparison: The species bulbosa has the same appendage arrangement and archeophyllar position as cinctum, but differs from it in its significantly smaller dimensions and different appendage structure.
It will be very difficult to verify how many of the specimens described in the literature under Hystridiosphaeridium tubiferum EHRENBERG should be classified as Hystrichokolpoma bulbosa. With an unfavorable position in the preparation (belt lateral), the majority of specimens possessing an appendage type identical to that of tubiferum can be very difficult to identify.
Combination not validly published: specific name not validly published and combination not intended. NOW Hystrichokolpoma bulbosum. Originally Xanthidium bulbosum, subsequently Hystrichosphaera bulbosa (combination not validly published), thirdly Hystrichosphaeridium bulbosum, fourthly Ovum hispidum bulbosum (combination not validly published), fifthly (and now) Hystrichokolpoma bulbosum, sixthly Baltisphaeridium bulbosum (combination not validly published).
Taxonomic senior synonym: Xanthidium (as Hystrichosphaeridium) tubiferum, according to Stover and Evitt (1978, p.55) — however, Lentin and Williams (1981, p.134) retained Xanthidium (as Hystrichokolpoma) bulbosum.
Downie and Sarjeant (1965, p.174) gave the citation "O. [Ovum] hispidum bulbosum (Ehrenberg, 1838a [1837b herein]) Lohmann, 1904, now Hystrichosphaeridium." However, we have not been able to locate the combination Ovum hispidum subsp. bulbosum in Lohmann (1904).
Holotype: Ehrenberg, 1837b, pl.1, fig.17.
Neotype: Morgenroth, 1968, pl.44, fig.6, designated by Morgenroth (1968, p.546).
Age: Danian.
---------------------------------------------------------------------------------------------------------------------------------------------------
Emendation [Morgenroth, 1968] (translated from German):
After examining numerous specimens from the Danien (see below), it is essential to define the species by means of a clearly oriented neotype with recognizable species and genus characteristics (dorsal and ventral apical appendages). Since the arrangement of the processes cannot be reliably determined on the specimen illustrated by EHRENBERG (so that it is insufficient as a type!), a neotype is hereby established which occupies a central position within the range of variation of the species and exhibits all important characteristics. The specimen preserved in Prep. KG10 and illustrated on Pl. 44, Fig. 6 is selected as the neotype.
Type locality: Kjölby Gaard, Hunstrup NW Thisted (Denmark).
Type stratum: Danian A.
Diagnosis: A species of the genus Hystrichokolpoma with the following pattern of process arrangement: 6', 6", 7, 7"', 2π, ππλ, 1"". Theca globular to distinctly ellipsoid. Theca surface weakly granulated. Girdle left-spiraling.
Process structure: Usually relatively tall, slender, distally trumpet-shaped, structureless. The distal margin is usually toothed (= "tubiferum process type"!). The base contours of the processes are usually separated from each other on the theca by larger spaces.
Within the range of variation, the processes can broaden considerably at the base, so that their basal contours are only separated from each other by narrow strips (bulbosa-process type!). The broadening of the processes is regularly accompanied by a shortening.
Archeopyle: Splitting of the apical polar cap with 2'-6'.
Description: The surface of the weakly ellipsoidal to spherical theca is granulated. In the apex region are 6 apical processes, of which 1' lies in the extension of the longitudinal field and is somewhat elongated in its direction. The other 5 apical processes are shed with the apical polar cap during pylode formation (see Plate 44, Fig. 6). Towards the girdle follow 6 relatively broad processes, which are to be regarded as pracequatorial processes. The girdle is covered with 7 processes, of which 1-6 are elongated at the base in the direction of the girdle, with the exception of 7, which has a circular base Below the girdle are seven post-equatorial processes (1"' and 2"' are very slender with a narrow base, 3"'-6"' are relatively voluminous, and 7'" is again very slender). Two robust intercalary processes lie below 1'" and 7'". One process is located on the hypothecal part of the longitudinal field. The antapex is characterized by a robust antapical process. The arrangement of the processes can be seen in Figures 6 and 7 on Plate 44.
Dimensions:
Theca lengths: 34 μ (31 μ/43 μ)
Theca width: 30 μ (25 μ/33 μ)
Process length: approx. 14-22 μ (6 μ/31 μ)
(100 measurements)
Number of specimens examined: 750
Comparison: The species bulbosa has the same appendage arrangement and archeophyllar position as cinctum, but differs from it in its significantly smaller dimensions and different appendage structure.
It will be very difficult to verify how many of the specimens described in the literature under Hystridiosphaeridium tubiferum EHRENBERG should be classified as Hystrichokolpoma bulbosa. With an unfavorable position in the preparation (belt lateral), the majority of specimens possessing an appendage type identical to that of tubiferum can be very difficult to identify.