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Pareodinia trinetra
Pareodinia trinetron (Sarjeant, 1966) Below, 1990
Originally Netrelytron, subsequently Kalyptea, thirdly (and now) Pareodinia.
Taxonomic senior synonym: Netrelytron (as and now Kalyptea) stegastum, according to Poulsen (1996, p.61).
Taxonomic junior synonym: Netrelytron parum, according to Wiggins (1975, p.110) — however, Netrelytron parum is now considered a taxonomic junior synonym of Netrelytron (now Kalyptea) stegastum. Sarjeant (1966c) stated that the epithet was derived from the Greek tri = three and netron = spindle. Since Principle 5 of the I.C.N. states that taxon names are to be treated as Latin and since compound epithets are conventionally treated as adjectives, the epithet should be rendered as trinetra in agreement with the feminine gender of the generic name
Holotype: Sarjeant, 1966, pl.22, fig.3
Locus typicus: Speeton Clat, West Heslerton, England
Stratum typicum: Middle Barremian
Original diagnosis: Sarjeant, 1966, p. 199-200: Netrelytron trinetron
A Netrelytron with outer body of basically ovoidal shape, giving rise to strongly tapering, conical apical horn and somewhat shorter, conical antapical horn. Shape of inner body exactly similar. Horns polar and axial in position and direction. Endophragm and periphragm minutely, but densely, granular. antapical horn represented by slight protuberance on left antapical margin. Capsule thick walled, often coarsely granular. Processes extremely short on ambitus of periphragm and increasing in length further away from ambitus. Distally processes bifid, aculeate, acuminate or evexate.
Dimensions: holotype: overall length of enclosing body 90 µm, breadth 53.5 µm, length of apical horn 18 µm, of antapical horn 5 µm; overall length of inner body 67.5 µm, breadth 38.5 µm. Range of dimensions; overall length of enclosing body ca.70-95 µm.
Original description: Sarjeant, 1966, p. 200: Netrelytron trinetron
The holotype is enclosed in a spindle-shaped cloak of debris: in other specimens, the debris cloak appears less well formed. The outer membrane is spindle-shaped, with unequally developed horns. In the holotype, the apical horn tapers sharply to an acute point from about mid-length: this was not the case in other specimens, where the apical horn tapered more smoothly from base to tip. The inner body is of comparable shape, its apical horn always tapering smoothly from base to tip. No specimen seen shows a well-developed archaeopyle; however, the holotype shows a slit, corresponding in position to a precingular opening, which may be an archaeopyle that has either incompletely opened or subsequently closed up.
Originally Netrelytron, subsequently Kalyptea, thirdly (and now) Pareodinia.
Taxonomic senior synonym: Netrelytron (as and now Kalyptea) stegastum, according to Poulsen (1996, p.61).
Taxonomic junior synonym: Netrelytron parum, according to Wiggins (1975, p.110) — however, Netrelytron parum is now considered a taxonomic junior synonym of Netrelytron (now Kalyptea) stegastum. Sarjeant (1966c) stated that the epithet was derived from the Greek tri = three and netron = spindle. Since Principle 5 of the I.C.N. states that taxon names are to be treated as Latin and since compound epithets are conventionally treated as adjectives, the epithet should be rendered as trinetra in agreement with the feminine gender of the generic name
Holotype: Sarjeant, 1966, pl.22, fig.3
Locus typicus: Speeton Clat, West Heslerton, England
Stratum typicum: Middle Barremian
Original diagnosis: Sarjeant, 1966, p. 199-200: Netrelytron trinetron
A Netrelytron with outer body of basically ovoidal shape, giving rise to strongly tapering, conical apical horn and somewhat shorter, conical antapical horn. Shape of inner body exactly similar. Horns polar and axial in position and direction. Endophragm and periphragm minutely, but densely, granular. antapical horn represented by slight protuberance on left antapical margin. Capsule thick walled, often coarsely granular. Processes extremely short on ambitus of periphragm and increasing in length further away from ambitus. Distally processes bifid, aculeate, acuminate or evexate.
Dimensions: holotype: overall length of enclosing body 90 µm, breadth 53.5 µm, length of apical horn 18 µm, of antapical horn 5 µm; overall length of inner body 67.5 µm, breadth 38.5 µm. Range of dimensions; overall length of enclosing body ca.70-95 µm.
Original description: Sarjeant, 1966, p. 200: Netrelytron trinetron
The holotype is enclosed in a spindle-shaped cloak of debris: in other specimens, the debris cloak appears less well formed. The outer membrane is spindle-shaped, with unequally developed horns. In the holotype, the apical horn tapers sharply to an acute point from about mid-length: this was not the case in other specimens, where the apical horn tapered more smoothly from base to tip. The inner body is of comparable shape, its apical horn always tapering smoothly from base to tip. No specimen seen shows a well-developed archaeopyle; however, the holotype shows a slit, corresponding in position to a precingular opening, which may be an archaeopyle that has either incompletely opened or subsequently closed up.