Back
Deflandrea antarctica
Deflandrea antarctica Wilson, 1967
Holotype: Wilson, 1967, fig.23
Locus typicus: Erratics near Minna Bluff, McMurdo Sound, Antarctica
Stratum typicum: Early Tertiary, probably Eocene
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Deflandrea antarctica Wilson, 1967a, has an apical horn usually capped by a papilla. The antapical horns are short, approximately equal in size. The pericyst is granulate, the granules forming a dotted pattern. The periarcheopyle is isodeltaform to latideltaform, the endoarcheopyle is latideltaform. Deflandrea antarctica differs from D. phosphoritica in having a much more broadly rounded epicyst. Wrenn and Hart (1988) recognized two types based on ornament type and distribution.
--------------------------------------------------
Original description: Wilson, 1967, p.58-59
Test peridinoid in shape, bi- layered, divided into epitheca and hypotheca by a slightly laevorotatory transverse girdle. Apical horn broad at base, narrow at apex which is usually capped with a small papilla; antapical horns short, approximately equal in size. Outer cyst usually covered with numerous granules forming a dotted pattern. Inner cyst fairly thich- walled, smooth, and approximately circular in outline. Archeopyle broad, intercalary, subhexagonal. Operculum free, bi-layered; inner layer smaller, denser, and of more regular shape than the membranous outer layer; the large and small layers of the operculum represent segments of the outer and inner cysts respectively. Apparantly atabulate, although granules sometimes concentrated into polygonal clusters possibly indicative of reflected tabulation.
Dimensions: Holotype l = 138 µm, b = 72 µm, diameter of inner cyst 69 µm.
Range l = 110(130)152 µm, b = 72(84)91 µm (7 specimens).
Discussion:Wilson, 1967, p.59
Deflandrea antarctica broadly resembles D. robusta Deflandre and Cookson, but has a more coarsely textured outer cyst and much broader archeopyle. It differs from D. phosphoritica in having a much more broadly rounded epitheca. The species was recorded as Deflandrea aff. bakeri in the preliminary species list of McIntyre and Wilson, 1966. Detached archeopyle opercula of D. antarctica are common and distinctive and provide a method of recognising the presence of the species even in the absence of the parent cyst.
Holotype: Wilson, 1967, fig.23
Locus typicus: Erratics near Minna Bluff, McMurdo Sound, Antarctica
Stratum typicum: Early Tertiary, probably Eocene
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Deflandrea antarctica Wilson, 1967a, has an apical horn usually capped by a papilla. The antapical horns are short, approximately equal in size. The pericyst is granulate, the granules forming a dotted pattern. The periarcheopyle is isodeltaform to latideltaform, the endoarcheopyle is latideltaform. Deflandrea antarctica differs from D. phosphoritica in having a much more broadly rounded epicyst. Wrenn and Hart (1988) recognized two types based on ornament type and distribution.
--------------------------------------------------
Original description: Wilson, 1967, p.58-59
Test peridinoid in shape, bi- layered, divided into epitheca and hypotheca by a slightly laevorotatory transverse girdle. Apical horn broad at base, narrow at apex which is usually capped with a small papilla; antapical horns short, approximately equal in size. Outer cyst usually covered with numerous granules forming a dotted pattern. Inner cyst fairly thich- walled, smooth, and approximately circular in outline. Archeopyle broad, intercalary, subhexagonal. Operculum free, bi-layered; inner layer smaller, denser, and of more regular shape than the membranous outer layer; the large and small layers of the operculum represent segments of the outer and inner cysts respectively. Apparantly atabulate, although granules sometimes concentrated into polygonal clusters possibly indicative of reflected tabulation.
Dimensions: Holotype l = 138 µm, b = 72 µm, diameter of inner cyst 69 µm.
Range l = 110(130)152 µm, b = 72(84)91 µm (7 specimens).
Discussion:Wilson, 1967, p.59
Deflandrea antarctica broadly resembles D. robusta Deflandre and Cookson, but has a more coarsely textured outer cyst and much broader archeopyle. It differs from D. phosphoritica in having a much more broadly rounded epitheca. The species was recorded as Deflandrea aff. bakeri in the preliminary species list of McIntyre and Wilson, 1966. Detached archeopyle opercula of D. antarctica are common and distinctive and provide a method of recognising the presence of the species even in the absence of the parent cyst.