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Chichaouadinium limpidum
Chichaoaudinium limpidum, (Singh, 1971), Below, 1981
Tax. jr. synonym of Spinidinium? (now Chichaouadinium) vestitum Brideaux, 1971, according to Lentin and Williams, 1973.
Holotype: Singh, 1971, pl.61, figs.1-2
Locus typicus: Peace River area, Alberta, Canada
Stratum typicum: Middle-Late Albian
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Original description as Deflandrea limpida: [Singh, 1971, p. 359-360]:
Description:
Test dorsoventrally compressed with elongated pentagonal outline;
epitract conical with a blunt apex representing the apical horn; hypotract with a widebased, pointed, reduced antapical horn on the left side and a rudimentary one, often marked by a small bulge, on the right side;
body with a thin-walled capsule; capsule spherical, smooth, hyaline, and filling the body cavity laterally; capsule almost imperceptible in some specimens;
tabulation on the outer body wall faint; plates outlined by the breakdown of sutures and by rows of spinules and pila bordering the plates; tabulation pattern typically peridinoid (?4", 3a, 7", 5""", 2"""");
cingulum circular, bordered on either side by a ridge bearing spinules and pila, and dividing the test into a larger epitract and smaller hypotract; sulcus 12 to 15 µm wide, delimited on the ventral hypotract by two longitudinal ridges bearing spinules and pila, and on the epitract by two longitudinal rows of spinules and pila;
archeopyle intercalary, hexagonal, formed by the loss of plate 2a; operculum often in position;
outer wall ornamented by 0.5-1.5 µm long, conical spinules, short blunt rods, and round-headed pila; spinules and pila forming a circlet at the apex, bordering the plates, cingulum, and sulcus, and also occurring on the plates; outer wall membranous and less than 0.5 µm thick.
Dimensions:
Size range: Total length of the test, including the horns (38 specimens) 43(61)75 µm. Holotype 72 µm.
Total breadth of the test (35 specimens) 33(43)50 µm. Holotype 41 µm.
Length of the capsule (9 specimens) 24(32)36 µm. Holotype 36 µm.
Breadth of the capsule (9 specimens) 32(38)42 µm. Holotype 40 µm.
Affinities: (p. 360-361):
Deflandrea limpida is characterized by a very hyaline capsule which is almost imperceptible in unstained specimens.
Deflandrea echinoidea Cookson and Eisenack, 1960, resembles D. Iimpida, but differs in having a more circular outline, a prominently developed antapical horn, up to 5-micron long, randomly distributed, stiff spines, a sulcus restricted to the ventral hypotract, and a nontabulate body. Deflandrea svetdrupiana Manum, 1962, can be easily distinguished from D. Iimpida in possessing a broken cingulum, and a prominently developed antapical horn.
Tax. jr. synonym of Spinidinium? (now Chichaouadinium) vestitum Brideaux, 1971, according to Lentin and Williams, 1973.
Holotype: Singh, 1971, pl.61, figs.1-2
Locus typicus: Peace River area, Alberta, Canada
Stratum typicum: Middle-Late Albian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Deflandrea limpida: [Singh, 1971, p. 359-360]:
Description:
Test dorsoventrally compressed with elongated pentagonal outline;
epitract conical with a blunt apex representing the apical horn; hypotract with a widebased, pointed, reduced antapical horn on the left side and a rudimentary one, often marked by a small bulge, on the right side;
body with a thin-walled capsule; capsule spherical, smooth, hyaline, and filling the body cavity laterally; capsule almost imperceptible in some specimens;
tabulation on the outer body wall faint; plates outlined by the breakdown of sutures and by rows of spinules and pila bordering the plates; tabulation pattern typically peridinoid (?4", 3a, 7", 5""", 2"""");
cingulum circular, bordered on either side by a ridge bearing spinules and pila, and dividing the test into a larger epitract and smaller hypotract; sulcus 12 to 15 µm wide, delimited on the ventral hypotract by two longitudinal ridges bearing spinules and pila, and on the epitract by two longitudinal rows of spinules and pila;
archeopyle intercalary, hexagonal, formed by the loss of plate 2a; operculum often in position;
outer wall ornamented by 0.5-1.5 µm long, conical spinules, short blunt rods, and round-headed pila; spinules and pila forming a circlet at the apex, bordering the plates, cingulum, and sulcus, and also occurring on the plates; outer wall membranous and less than 0.5 µm thick.
Dimensions:
Size range: Total length of the test, including the horns (38 specimens) 43(61)75 µm. Holotype 72 µm.
Total breadth of the test (35 specimens) 33(43)50 µm. Holotype 41 µm.
Length of the capsule (9 specimens) 24(32)36 µm. Holotype 36 µm.
Breadth of the capsule (9 specimens) 32(38)42 µm. Holotype 40 µm.
Affinities: (p. 360-361):
Deflandrea limpida is characterized by a very hyaline capsule which is almost imperceptible in unstained specimens.
Deflandrea echinoidea Cookson and Eisenack, 1960, resembles D. Iimpida, but differs in having a more circular outline, a prominently developed antapical horn, up to 5-micron long, randomly distributed, stiff spines, a sulcus restricted to the ventral hypotract, and a nontabulate body. Deflandrea svetdrupiana Manum, 1962, can be easily distinguished from D. Iimpida in possessing a broken cingulum, and a prominently developed antapical horn.