Back
Apteodinium spongiosum
Apteodinium spongiosum, McIntyre and Brideaux, 1980
Originally (and now) Apteodinium, subsequently Aldorfia. Davey, 1982b, transferred this species to Aldorfia Stover and Evitt, 1978. Lucas-Clark, 1987, retained it in Apteodinium.
Holotype: McIntyre and Brideaux, 1980, pl.2, figs.11-12; Jan du Chêne et al., 1986, pl.8, figs.4-5.
Locus typicus: Martin Creek, District of Mackenzie, Canada
Stratum typicum: Valanginian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [McIntyre and Brideaux, 1980, p. 12]:
Diagnosis:
Shape: Pericyst - Ambitus ovoid, elongated longitudinally; prolonged into a stout apical horn, 11-18 µm long. Slight dorsoventral compression. Endocyst - Arnbitus ovoid, elongate longitudinally, rounded apically or with a very small apical prominence. Slight dorsoventral compression. Pericoels: Pericyst and endocyst in close contact except at the position of the apical horn.
Phragma: Periphragm - Variable thickness, sponge-like thickenings forming a complex scrollwork projecting up to 2.0 µm above the endophragm, set off by narrow, twisting channels of thinner periphragm; scrollwork absent on the apical horn. Endophragm - About 0.5 µm thick, apparently smooth.
Paratabulation:
Pericyst - Scrollwork pattern appears to bear no relation to paratabulation.
Pericingulum - Observed on only a few specimens; denoted by a broad band of semi-aligned ridges of raised periphragm, up to 12 µm wide, the band offset about one half a pericingulum width.
Perisulcus - Observed on only a few specimens; denoted by a reduction or absence of raised periphragm, this region narrow anteriorly, widening posteriorly.
Endocyst - Paratabulation not observed.
Archeopyle: Precingular, Type P(3"). Operculum simple, free, rounded-polygonal and somewhat elongate in shape.
Dimensions:
Percyst length - 80-118 µm; width - 63-75 µm.
Affinities:
Concerning Apteodinium granulatum, Eisenack, (1958, p. 386, translation) comments that its wall is ". . .+ strongly granulated, varying in thickness, thin to moderately thick, up to 4 µm . . .; The granulation of the wall appears to be produced by an alveolar structure...". From this description It appears that Apteodinium spongiosum and Apteodlnium granulatum Eisenack, 1958 are similar in wall structure and general morphology. Apteodinium spongiosum differs, however, in possessing an elaborate scrollwork pattern of raised periphragm and also is larger.
Originally (and now) Apteodinium, subsequently Aldorfia. Davey, 1982b, transferred this species to Aldorfia Stover and Evitt, 1978. Lucas-Clark, 1987, retained it in Apteodinium.
Holotype: McIntyre and Brideaux, 1980, pl.2, figs.11-12; Jan du Chêne et al., 1986, pl.8, figs.4-5.
Locus typicus: Martin Creek, District of Mackenzie, Canada
Stratum typicum: Valanginian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [McIntyre and Brideaux, 1980, p. 12]:
Diagnosis:
Shape: Pericyst - Ambitus ovoid, elongated longitudinally; prolonged into a stout apical horn, 11-18 µm long. Slight dorsoventral compression. Endocyst - Arnbitus ovoid, elongate longitudinally, rounded apically or with a very small apical prominence. Slight dorsoventral compression. Pericoels: Pericyst and endocyst in close contact except at the position of the apical horn.
Phragma: Periphragm - Variable thickness, sponge-like thickenings forming a complex scrollwork projecting up to 2.0 µm above the endophragm, set off by narrow, twisting channels of thinner periphragm; scrollwork absent on the apical horn. Endophragm - About 0.5 µm thick, apparently smooth.
Paratabulation:
Pericyst - Scrollwork pattern appears to bear no relation to paratabulation.
Pericingulum - Observed on only a few specimens; denoted by a broad band of semi-aligned ridges of raised periphragm, up to 12 µm wide, the band offset about one half a pericingulum width.
Perisulcus - Observed on only a few specimens; denoted by a reduction or absence of raised periphragm, this region narrow anteriorly, widening posteriorly.
Endocyst - Paratabulation not observed.
Archeopyle: Precingular, Type P(3"). Operculum simple, free, rounded-polygonal and somewhat elongate in shape.
Dimensions:
Percyst length - 80-118 µm; width - 63-75 µm.
Affinities:
Concerning Apteodinium granulatum, Eisenack, (1958, p. 386, translation) comments that its wall is ". . .+ strongly granulated, varying in thickness, thin to moderately thick, up to 4 µm . . .; The granulation of the wall appears to be produced by an alveolar structure...". From this description It appears that Apteodinium spongiosum and Apteodlnium granulatum Eisenack, 1958 are similar in wall structure and general morphology. Apteodinium spongiosum differs, however, in possessing an elaborate scrollwork pattern of raised periphragm and also is larger.