Stratigraphy, sedimentology, and paleoecology of Upper Cretaceous/Paleocene shelf-deltaic sediments of Seymour Island

The Cretaceous and Paleocene pleurotomariid (Gastropoda: Vetigastropoda) fauna of Seymour Island, Antarctica

Journal of Paleontology ◽

10.1666/09-004.1 ◽

2009 ◽

Vol 83 (5) ◽

pp. 750-766 ◽

Cited By ~ 5

Author(s):

M. G. Harasewych ◽

Anton Oleinik ◽

William Zinsmeister

Keyword(s):

Species Richness ◽

New Zealand ◽

South America ◽

Late Cretaceous ◽

Upper Cretaceous ◽

Southern India ◽

New Combination ◽

The Family ◽

The Status ◽

Seymour Island

Leptomaria antipodensis and Leptomaria hickmanae are described from the Upper Cretaceous [Maastrichtian] Lopez de Bertodano Formation, Seymour Island, and represent the first Mesozoic records of the family Pleurotomariidae from Antarctica. Leptomaria stillwelli, L. seymourensis, Conotomaria sobralensis and C. bayeri, from the Paleocene [Danian], Sobral Formation, Seymour Island, are described as new. Leptomaria larseniana (Wilckens, 1911) new combination, also from the Sobral Formation, is redescribed based on better-preserved material. The limited diversity of the pleurotomariid fauna of Seymour Island is more similar to that of the Late Cretaceous faunas of Australia and New Zealand in terms of the number of genera and species, than to the older, more diverse faunas of South America, southern India, or northwestern Madagascar, supporting the status of the Weddelian Province as a distinct biogeographic unit. The increase in the species richness of this fauna during the Danian may be due to the final fragmentation of Gondwana during this period.

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Large heteromorph ammonites from the Upper Cretaceous of Seymour Island, Antarctica

Journal of Paleontology ◽

10.1017/s0022336000041251 ◽

1989 ◽

Vol 63 (5) ◽

pp. 626-636 ◽

Cited By ~ 25

Author(s):

Eduardo B. Olivero ◽

William J. Zinsmeister

Keyword(s):

Upper Cretaceous ◽

Flat Surface ◽

Center Of Mass ◽

The Body ◽

Total Density ◽

Nacreous Layer ◽

Shell Wall ◽

Body Chamber ◽

Large Size ◽

Seymour Island

Two species of the heteromorph ammonite genus Diplomoceras Hyatt are described from the Upper Cretaceous of the James Ross–Seymour Islands area, Antarctica. The late Campanian–early Maastrichtian D. lambi Spath has a relatively high rib density, whereas D. maximum n. sp. has a lower rib density and is known only from the uppermost Maastrichtian of the Lopez de Bertodano Formation on Seymour Island. Both species attain an exceptionally large size with the body chamber of D. maximum n. sp. attaining a length in excess of one meter. The structure of the shell wall in Diplomoceras is characterized by the thickening of the nacreous layer below the ribs. The shell thickening results in an inner flat surface and a smooth phragmocone. Reconstruction of the shell suggests at least four parallel shafts and three U-connectives. Estimates of the total density, center of buoyancy, and center of mass in this reconstructed shell indicate a slightly positive buoyant shell with a relatively unstable floating position.

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Microplankton from the Cape Lamb Member, López de Bertodano Formation (Upper Cretaceous), Cape Lamb, Vega Island

Antarctic Science ◽

10.1017/s095410209200049x ◽

1992 ◽

Vol 4 (3) ◽

pp. 337-353 ◽

Cited By ~ 17

Author(s):

Sandy W. Smith

Keyword(s):

Antarctic Peninsula ◽

Upper Cretaceous ◽

Lower Zone ◽

Dinoflagellate Cyst ◽

Seymour Island

Samples from the lower Cape Lamb Member, López de Bertodano Formation, Cape Lamb, Vega Island, Antarctic Peninsula have yielded rich and diverse marine palynofloral assemblages. The overall character of the palynofloral assemblages indicate a latest Campanian–earliest Maastrichtian age. Four new dinoflagellate cyst species Canninginopsis ordospinosa sp. nov., Microdinium ? gymnosuturum sp. nov., Phelodinium exilicornutum sp. nov. and Operculodinium radiculatum sp. nov. are described. Certain key dinoflagellate cyst taxa such as Operculodinium radiculatum sp. nov., Manumiella n. sp. 3 and Isabelidinium cretaceum allow a correlation of the lower Cape Lamb Member with the upper palynomorph zone 1/lower zone 2 on nearby Seymour Island.

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