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Ectosphaeropsis
From Williams et al., 2017:
[Ectosphaeropsis, Londeix and Jan du Chêne, 1988, p. 252-253
Type species: Ectosphaeropsis burdigalensis, Londeix and Jan du Chêne, 1988 ( pl.1, figs.1–5)]
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Original description: [Londeix and Jan du Chêne, 1988]: (Translation: Fensome et al., 1991, p. 193 (diagnosis) and LPP):
Diagnosis:
Cyst spiniferate with a subspheroidal to ellipsoidal central body. The wall comprises an endophragm and a periphragm closely appressed except at the processes, which are formed from the periphragm. The processes are gonal (possibly intergonal), and may or may not be connected at their base by septa. Distally, they are trifurcate, then bifurcate and are interconnected by trabeculae which form the framework of an ectophragm entirely enveloping the cyst. The polar processes may sometimes be differentiated.
The paratabulation is of gonyaulacoid type: 0-2pr, 3-4`, 6``, 6c, xs, 5-6```, 1p, 1````.
The archeopyle is precingular, of type P (3``). The operculum is free.
Affinities:
ectophr. trabec. septa ectocoel pericoel
Ectosphaeropsis + + +/- + -
Nematosphaeropsis - + +/- - -
Cannosphaeropsis - + - - -
Hystrichostrogylon - - +/- - +
Spiniferites - - + - -
Achomosphaera - - - - -
Ectosphaeropsis differs from all other genera belonging to the "Spiniferites complex" sensu Evitt, 1985, in the simultaneous presence of a network of trabeculae and an ectophragm enveloping the cyst completely.
Spiniferites Mantell, 1850, emend. Sarjeant, 1970 and Achomosphaera Evitt, 1963 possess neither an ectophragm nor a network of trabeculae.
Cannosphaeropsis O. Wetzel, 1933, emend. Duxbury, 1980, developing a network of simple trabeculae, differs from Ectosphaeropsis in a smaller number of processes as well as in the absence of an ectophragm. Furthermore, the central body of the representatives of that genus consist of an autophragm only.
Ectosphaeropsis has a similar network of trabeculae as encountered in Nematosphaeropsis Deflandre and Cookson, 1955, emend. Williams and Downie, 1966, but in the latter genus the trabeculae never support an ectophragm.
The endophragm and periphragm of Hystrichostrogylon Agelopoulos, 1964, emend. Stover and Evitt, 1978 delimit a large pericoeel, but not an ectocoel like in Ectosphaeropsis.
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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.
Ectosphaeropsis Londeix and Jan du Chêne, 1988, is an S-type cyst with the tabulation 0-2pr, 3-4`, 6", 6c, xs, 5-6"' , 1p, 1"''. The processes are gonal, possibly also intergonal, and may be connected at their base by septa. Distally they are trifurcate, then bifurcate and are interconnected by trabeculae which form an all-enveloping ectophragm. Apical polar process often distinctive and larger. Archeopyle P, resulting from the loss of the 3".
[Ectosphaeropsis, Londeix and Jan du Chêne, 1988, p. 252-253
Type species: Ectosphaeropsis burdigalensis, Londeix and Jan du Chêne, 1988 ( pl.1, figs.1–5)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Londeix and Jan du Chêne, 1988]: (Translation: Fensome et al., 1991, p. 193 (diagnosis) and LPP):
Diagnosis:
Cyst spiniferate with a subspheroidal to ellipsoidal central body. The wall comprises an endophragm and a periphragm closely appressed except at the processes, which are formed from the periphragm. The processes are gonal (possibly intergonal), and may or may not be connected at their base by septa. Distally, they are trifurcate, then bifurcate and are interconnected by trabeculae which form the framework of an ectophragm entirely enveloping the cyst. The polar processes may sometimes be differentiated.
The paratabulation is of gonyaulacoid type: 0-2pr, 3-4`, 6``, 6c, xs, 5-6```, 1p, 1````.
The archeopyle is precingular, of type P (3``). The operculum is free.
Affinities:
ectophr. trabec. septa ectocoel pericoel
Ectosphaeropsis + + +/- + -
Nematosphaeropsis - + +/- - -
Cannosphaeropsis - + - - -
Hystrichostrogylon - - +/- - +
Spiniferites - - + - -
Achomosphaera - - - - -
Ectosphaeropsis differs from all other genera belonging to the "Spiniferites complex" sensu Evitt, 1985, in the simultaneous presence of a network of trabeculae and an ectophragm enveloping the cyst completely.
Spiniferites Mantell, 1850, emend. Sarjeant, 1970 and Achomosphaera Evitt, 1963 possess neither an ectophragm nor a network of trabeculae.
Cannosphaeropsis O. Wetzel, 1933, emend. Duxbury, 1980, developing a network of simple trabeculae, differs from Ectosphaeropsis in a smaller number of processes as well as in the absence of an ectophragm. Furthermore, the central body of the representatives of that genus consist of an autophragm only.
Ectosphaeropsis has a similar network of trabeculae as encountered in Nematosphaeropsis Deflandre and Cookson, 1955, emend. Williams and Downie, 1966, but in the latter genus the trabeculae never support an ectophragm.
The endophragm and periphragm of Hystrichostrogylon Agelopoulos, 1964, emend. Stover and Evitt, 1978 delimit a large pericoeel, but not an ectocoel like in Ectosphaeropsis.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Ectosphaeropsis Londeix and Jan du Chêne, 1988, is an S-type cyst with the tabulation 0-2pr, 3-4`, 6", 6c, xs, 5-6"' , 1p, 1"''. The processes are gonal, possibly also intergonal, and may be connected at their base by septa. Distally they are trifurcate, then bifurcate and are interconnected by trabeculae which form an all-enveloping ectophragm. Apical polar process often distinctive and larger. Archeopyle P, resulting from the loss of the 3".