Back
Apteodinium thelium
Apteodinium thelium, Sarjeant, 1985
Tax. jr. synonym of Apteodinium granulatum Eisenack, 1958, according to Jan du Chêne et al., 1986. Sarjeant (pers. comm.) in Lentin and Williams, 1989, retained Apteodinium thelium as a separate species.
Holotype: Sarjeant, 1985, pl.8, figs.3-4
Paratype: Sarjeant, 1985
Locus typicus: borehole at Marne, Feld Heide, N Germany
Stratum typicum: Late Aptian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Sarjeant, 1985, p. 83]:
Diagnosis:
Proximate, cryprotabulate cysts, monocornucavate. Ambitus longate-ovoidal to broadly ellipsoidal. Epitract slightly smaller than hypotract, showing some degree of apical flattening and giving rise to a small horn of nipple-like shape and proportionate size.
Apical horn formed from periphragm only, there being no outbulge of the endophragm into its base. Hypotract in the form of a hemiellipsoid, without horns.
Cingulum shallowly indented, its margins marked by very low ridges; feebly laevorotatory, its two ends differing in anteroposterior position by its width.
Sulcus shallowly indented and broad; its posterior margins are marked by low ridges, but these fade out anteriorly.
Some paraplate margins are similarly marked, but not sufficiently completely so for the paratabulation to be ascertained. Surface of phragma densely and coarsely granulate.
Archaeopyle single-plate precingular (type P), formed by loss of a portion of the dorsal surface corresponding to paraplate 3".
Dimensions:
Holotype: overall length 72 µm, length of horn 6.5 µm, overall breadth 54 µm.
Paratype: overall length 67 µm, length of horn 5.5 µm, overall breadth 45 µm. Five specimens measured.
Affinities: (p.84):
The specimens placed into this new species differ consistently from A. granulatum, as herein redefined, in ambitus, style of apical horn, better marked cingulum and sulcus, and partial expression of a paratabulation. (The indentation of the sulcus is seen especially well in the paratype.)
Tax. jr. synonym of Apteodinium granulatum Eisenack, 1958, according to Jan du Chêne et al., 1986. Sarjeant (pers. comm.) in Lentin and Williams, 1989, retained Apteodinium thelium as a separate species.
Holotype: Sarjeant, 1985, pl.8, figs.3-4
Paratype: Sarjeant, 1985
Locus typicus: borehole at Marne, Feld Heide, N Germany
Stratum typicum: Late Aptian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Sarjeant, 1985, p. 83]:
Diagnosis:
Proximate, cryprotabulate cysts, monocornucavate. Ambitus longate-ovoidal to broadly ellipsoidal. Epitract slightly smaller than hypotract, showing some degree of apical flattening and giving rise to a small horn of nipple-like shape and proportionate size.
Apical horn formed from periphragm only, there being no outbulge of the endophragm into its base. Hypotract in the form of a hemiellipsoid, without horns.
Cingulum shallowly indented, its margins marked by very low ridges; feebly laevorotatory, its two ends differing in anteroposterior position by its width.
Sulcus shallowly indented and broad; its posterior margins are marked by low ridges, but these fade out anteriorly.
Some paraplate margins are similarly marked, but not sufficiently completely so for the paratabulation to be ascertained. Surface of phragma densely and coarsely granulate.
Archaeopyle single-plate precingular (type P), formed by loss of a portion of the dorsal surface corresponding to paraplate 3".
Dimensions:
Holotype: overall length 72 µm, length of horn 6.5 µm, overall breadth 54 µm.
Paratype: overall length 67 µm, length of horn 5.5 µm, overall breadth 45 µm. Five specimens measured.
Affinities: (p.84):
The specimens placed into this new species differ consistently from A. granulatum, as herein redefined, in ambitus, style of apical horn, better marked cingulum and sulcus, and partial expression of a paratabulation. (The indentation of the sulcus is seen especially well in the paratype.)