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Avellodinium falsificum
Avellodinium falsificum, Duxbury, 1977
Originally (and now) Avellodinium, subsequently Callaiosphaeridium.
Below, 1981, transferred this species to Callaiosphaeridium Davey and Williams, 1966; however, Lentin and Williams, 1981, retained it in Avellodinium.
Tax. jr. synonym of Spiniferites ramosus? subsp. aulosphaeropsis (O.Wetzel, 1933b) Lentin and Williams, 1973, according to Sarjeant, 1985, who noted that Auellodinium falsificum must be retained, since a taxon does not have priority outside its rank.
Holotype: Duxbury, 1977, pl.5, figs.1-2; Fensome et al., 1993a, figs.1-2 - p.1171.
Locus typicus: Speeton Clay, Speeton, England.
Stratum typicum: Barremian
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Original description: [Duxbury, 1977, p. 25-26]:
Diagnosis:
A small, chorate cyst. The cyst body is ellipsoidal, smooth to finely granular and fairly thick-walled.
The periphragm is closely connected to the endophragm except where it is produced into gonal processes and sutural crests.
The processes are distally trifurcate, subsequently bifurcating once or twice to terminate in very slender, thread-like elements. Some cingular processes have a deep primary bifurcation.
Tabulation 3', 6", ?6c, 5''', lpv, 1'''', outlined by low sutural crests.
Sulcus broad, confined to hypotract.
Archeopyle epitractal, cingulum laevo-rotatory.
Description:
The endophragm is fairly thick and the periphragm is produced into gonal processes (no sutural processes were seen). These processes are usually proximally connected by low sutural crests. Occasionally, a few of the crests may be high and perforate. The difference in level between the free ends of the cingulum causes the splitting off of part of plate 6" during total removal of the epitract. Part of plate 6" therefore remains attached to the hypotract. Specimens are often seen where some splitting has occurred but where plate 6" is unbroken so that the two portions of the test remain attached.
Dimensions:
Holotype (complete) - Main body 37x35 µm; overall 63x63 µm. Range complete specimens - Main body 41(35)23x44(33)28 µm; overall 70(63)53x68(59)46 µm
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Avellodinium falsificum Duxbury, 1977. According to Duxbury (1977, p.250), this species has an ellipsoidal central body which is smooth to finely granular and fairly thick-walled. The tabulation is delineated by gonal processes and sutural crests. The processes are distally trifurcate, then bifurcate, as in Spiniferites ramosus. Some cingular processes have a deep primary bifurcation. Tabulation 3', 6", ?6c, 5"’, 1pv, 1"”. Sulcus broad, restricted to hypocyst. Archeopyle epicystal. Harding (1990, p.23) noted that there are also sutural processes. Further the archeopyle suture is planar and does not conform to the zig-zag margin of the cingulum, so that the operculum is reduced. The cyst wall is spongy or irregularly reticulate-foveate.
Size: overall 53-70 x 46-68 µm; central body 23-41 x 28-44 µm.
Originally (and now) Avellodinium, subsequently Callaiosphaeridium.
Below, 1981, transferred this species to Callaiosphaeridium Davey and Williams, 1966; however, Lentin and Williams, 1981, retained it in Avellodinium.
Tax. jr. synonym of Spiniferites ramosus? subsp. aulosphaeropsis (O.Wetzel, 1933b) Lentin and Williams, 1973, according to Sarjeant, 1985, who noted that Auellodinium falsificum must be retained, since a taxon does not have priority outside its rank.
Holotype: Duxbury, 1977, pl.5, figs.1-2; Fensome et al., 1993a, figs.1-2 - p.1171.
Locus typicus: Speeton Clay, Speeton, England.
Stratum typicum: Barremian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Duxbury, 1977, p. 25-26]:
Diagnosis:
A small, chorate cyst. The cyst body is ellipsoidal, smooth to finely granular and fairly thick-walled.
The periphragm is closely connected to the endophragm except where it is produced into gonal processes and sutural crests.
The processes are distally trifurcate, subsequently bifurcating once or twice to terminate in very slender, thread-like elements. Some cingular processes have a deep primary bifurcation.
Tabulation 3', 6", ?6c, 5''', lpv, 1'''', outlined by low sutural crests.
Sulcus broad, confined to hypotract.
Archeopyle epitractal, cingulum laevo-rotatory.
Description:
The endophragm is fairly thick and the periphragm is produced into gonal processes (no sutural processes were seen). These processes are usually proximally connected by low sutural crests. Occasionally, a few of the crests may be high and perforate. The difference in level between the free ends of the cingulum causes the splitting off of part of plate 6" during total removal of the epitract. Part of plate 6" therefore remains attached to the hypotract. Specimens are often seen where some splitting has occurred but where plate 6" is unbroken so that the two portions of the test remain attached.
Dimensions:
Holotype (complete) - Main body 37x35 µm; overall 63x63 µm. Range complete specimens - Main body 41(35)23x44(33)28 µm; overall 70(63)53x68(59)46 µm
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Avellodinium falsificum Duxbury, 1977. According to Duxbury (1977, p.250), this species has an ellipsoidal central body which is smooth to finely granular and fairly thick-walled. The tabulation is delineated by gonal processes and sutural crests. The processes are distally trifurcate, then bifurcate, as in Spiniferites ramosus. Some cingular processes have a deep primary bifurcation. Tabulation 3', 6", ?6c, 5"’, 1pv, 1"”. Sulcus broad, restricted to hypocyst. Archeopyle epicystal. Harding (1990, p.23) noted that there are also sutural processes. Further the archeopyle suture is planar and does not conform to the zig-zag margin of the cingulum, so that the operculum is reduced. The cyst wall is spongy or irregularly reticulate-foveate.
Size: overall 53-70 x 46-68 µm; central body 23-41 x 28-44 µm.