Leptogium Pirireisii, a new species of lichenized Ascomycota (Collemataceae) from James Ross Island in Antarctica

To date, Cretaceous nautilids from the Antarctic Peninsula have received little attention and only a single species had been reported, Eutrephoceras simile Spath, from Seymour, Snow Hill, and James Ross islands. Currently, it is considered a synonym of Eutrephoceras subplicatum (Steinmann), which has also been described from the Upper Cretaceous of central Chile, southern Argentina and Angola. Here, we report and describe E. subplicatum in detail, based on specimens from the Lower Campanian–Maastrichtian of Vega, Seymour and James Ross islands, presenting, for the first time, embryonic conch features related to the palaeoecology of these organisms. The nauta of this species had a diameter of approximately 30 mm with 5–6 septa. In addition, we describe a new species, Eutrephoceras antarcticum, and one specimen assigned to the same genus in open nomenclature, both recovered from the Lower Campanian beds of James Ross Island.

Download Full-text

Dinoflagellate cysts from the Rabot Member (Santa Marta Formation) of eastern James Ross Island

Antarctic Science ◽

10.1017/s0954102092000464 ◽

1992 ◽

Vol 4 (3) ◽

pp. 305-310 ◽

Cited By ~ 4

Author(s):

Paul W. Sumner

Keyword(s):

New Species ◽

Species Diversity ◽

Antarctic Peninsula ◽

Late Cretaceous ◽

Dinoflagellate Cysts ◽

Age Changes ◽

Dinoflagellate Cyst ◽

Low Diversity ◽

James Ross Island ◽

A New Species

Palynomorph assemblages dominated by dinoflagellate cysts are described from seventeen samples from the Rabot Member of the Santa Marta Formation at Ekelöf Point, eastern James Ross Island, Antarctic Peninsula. Although the assemblages are of relatively low diversity, the dinoflagellate cyst taxa recorded indicate a mid to late Campanian (Late Cretaceous) age. Changes in species diversity, dominance and gonyaulacacean ratio suggest a gradually reducing distance from shore during deposition, with a return to more offshore conditions towards the section top. A new species of dinoflagellate cyst, Isabelidinium papillum, is described.

Download Full-text

A new species of Antarctoxylon: a contribution to the early angiosperm ecosystem of Antarctica during the late Cretaceous

Antarctic Science ◽

10.1017/s095410201300076x ◽

2013 ◽

Vol 26 (4) ◽

pp. 371-376 ◽

Cited By ~ 4

Author(s):

Jakub Sakala ◽

Radek Vodrážka

Keyword(s):

New Species ◽

Late Cretaceous ◽

Growth Ring ◽

Unique Combination ◽

Early Angiosperm ◽

Livingston Island ◽

Lake Formation ◽

James Ross Island ◽

Perforation Plates ◽

A New Species

AbstractA new species of Antarctoxylon is described from the Coniacian Hidden Lake Formation of James Ross Island as A. mixai Sakala, sp. nov. This angiosperm fossil wood shows a unique combination of features in having indistinct growth ring boundaries, scalariform perforation plates with about 30 bars and rays both narrow (1–6-seriate) and very wide (up to 18-seriate). Its systematic affinities and exact living relative at the specific, generic or even familial level cannot be specified. Along with Weinmannioxylon nordenskjoeldii from James Ross Island and the angiosperm woods from the Williams Point on Livingston Island, this record provides further evidence of the earliest record of arboreal angiosperms in Antarctica.

Download Full-text