Monimiaceae sensu lato, an element of Gondwanan polar forests: Evidence from the late Cretaceous-early tertiary wood flora of Antarctica

2001 ◽  
Vol 14 (2) ◽  
pp. 207 ◽  
Author(s):  
Imogen Poole ◽  
Helmut Gottwald
Keyword(s):  
Late Cretaceous ◽  
Upper Cretaceous ◽  
First Record ◽  
Southern South America ◽  
Anatomical Features ◽  
Early Tertiary ◽  
Breadth Ratio ◽  
Ecological Dominance ◽  
Perforation Plates ◽  
The Antarctic

Palaeofloristic studies of the Antarctic Peninsula region are important in furthering our understanding of (i) the radiation and rise to ecological dominance of the angiosperms in the Southern Hemisphere during the Late Cretaceous and (ii) the present day disjunct austral vegetation. Investigations of Upper Cretaceous and Early Tertiary sediments of this region yield a rich assemblage of well-preserved fossil dicotyledonous angiosperm wood which provides evidence for the existence, since the Late Cretaceous, of temperate forests similar in composition to those found in present-day southern South America, New Zealand and Australia. This paper describes two previously unrecognised morphotypes, which can be assigned to the Monimiaceae sensu lato, and represents the first record of this family in the wood flora of Antarctica. Specimens belonging to the first fossil morphotype have been assigned to Hedycaryoxylon SÜss (subfamily Monimioideae) because they exhibit anatomical features characteristic of Hedycaryoxylon and extant Hedycarya J.R.Forst. &amp; G.Forst. and Tambourissa Sonn. Characters include diffuse porosity, vessels which are mainly solitary with scalariform perforation plates, opposite to scalariform intervascular pitting, paratracheal parenchyma, septate fibres and tall (>3 mm), wide multiseriate rays with a length: breadth ratio of approximately 1: 4. Specimens belonging to the second morphotype have been assigned to Atherospermoxylon KrÄusel, erected for fossil woods of the Monimiaceae in the tribe Atherospermeae (now Atherospermataceae) in that they exhibit anatomical features similar to Atherospermoxylon and extant Daphnandra Benth., Doryphora Endl. and Laurelia novae-zelandiae A.Cunn. These characters include diffuse to semi-ring porosity, scalariform perforation plates with up to 25 bars, septate fibres, relatively short (<1 mm) rays with a length: breadth ratio of between 1: 4 and 1: 11.

scholarly journals First record of Calappoidea and Dromioidea from the Upper Cretaceous (Upper Maastrichtian) of NW Madagascar

2003 ◽  
Vol 72 (2-3) ◽  
pp. 135-136
Author(s):  
Alessandro Garassino ◽  
Giovanni Pasini
Keyword(s):  
Late Cretaceous ◽  
Upper Cretaceous ◽  
First Record ◽  
Upper Maastrichtian

The crustaceans from the marine Berivotra Formation, dated as late Cretaceous, from 50 km south of Mahajanga, Madagascar contains macrurans, brachyurans and thalassinideans. Two brachyuran families, Raninidae and Dynomenidae, were previously identified with the genera Notopocorystes, Caloxanthus, Titanocarcinus, Xanthosia, and Dromiopsis. Fragmentary material now also allows the recognition of Dromioidea, Calappoidea and Xanthoidea.

scholarly journals Nannofossils, foraminifera and microforaminiferal linings in the Cenozoic diamictites of Cape Lamb, Vega Island, Antarctica

2014 ◽  
Vol 35 (1) ◽  
pp. 1-26 ◽  
Author(s):  
Andrea Concheyro ◽  
Andrea Caramés ◽  
Cecilia R. Amenábar ◽  
Marina Lescano
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
First Record ◽  
Organic Layer ◽  
Sediment Sources ◽  
Lower Maastrichtian ◽  
James Ross Island ◽  
The Antarctic ◽  
Upper Maastrichtian ◽  
Upper Campanian

AbstractMicropaleontological and palynological samples from three Cenozoic diamictites at Cape Lamb, Vega Island, James Ross Basin were analysed. Fossiliferous samples yielded reworked and autochthonous assemblages of Mesozoic calcareous nanno− fossils, impoverished Cretaceous foraminifera together with Neogene species, as well as Late Cretaceous dinoflagellate cysts, pollen, spores and abundant Cenozoic micro− foraminiferal linings. The recovered nannoflora indicates Early Cretaceous (Hauteri− vian-Albian) and Late Cretaceous (Santonian-Early Campanian) ages, suggesting an in− tensive reworking of marine sediments. The presence of the Early Cretaceous species Nannoconus circularis Deres et Acheriteguy in the diamictite represents its first record for the James Ross Basin. The scarce foraminiferal fauna includes Pullenia jarvisi Cushman, which indicates reworking from lower Maastrichtian-lower Paleocene sediments, and also the Neogene autochthonous Trochammina sp. aff. T. intermedia. The in− ner−organic layer observed inside this specimen appears to be identical to microfora− miniferal linings recovered from the same sample. Palynomorphs found in the studied samples suggest erosion from the underlying Snow Hill Island and the Lopez de Bertodano Formation beds (upper Campanian-upper Maastrichtian). These recovered assemblages indicate either different periods of deposition or reworking from diverse sources during Cenozoic glaciation, originating in James Ross Island and the Antarctic Peninsula with the influence of local sediment sources.

An ankylosaurid dinosaur from the Upper Cretaceous of Shandong (China)

1995 ◽  
Vol 132 (6) ◽  
pp. 683-692 ◽  
Author(s):  
Eric Buffetaut
Keyword(s):  
Late Cretaceous ◽  
Upper Cretaceous ◽  
First Record ◽  
Northwestern China ◽  
Left Femur ◽  
Caudal Vertebrae ◽  
The University

AbstractIn 1923, H. C. T’an and O. Zdansky collected remains of an ankylosaurid dinosaur in the Late Cretaceous Wangshi Group of the Laiyang region, in eastern Shandong (China). Apart from a few caudal vertebrae, this material, which is kept at the Palaeontological Institution of the University of Uppsala (Sweden), was never described or figured. It includes a well-preserved sacrum with the attached right ilium and part of the presacral rod, caudal vertebrae, a left femur and a dermal scute. This material is referred to an ankylosaurid of the genus Pinacosaurus Gilmore, 1933, on the basis of the widely divergent ilium bearing a strong ventral ridge and of the slenderness of the femur. In the absence of cranial material, a specific attribution is difficult and the Uppsala material is referred to as Pinacosaurus cf. grangeri (P. grangeri being the only generally accepted species of Pinacosaurus). This is the first record of Pinacosaurus outside the Gobi Basin of Mongolia and northwestern China. In the Gobi Basin, Pinacosaurus has been reported only from the Djadokhta Formation or its equivalents, of supposed Campanian age, and it is suggested that at least the part of the Wangshi Group which yielded the Shandong Pinacosaurus may be of roughly the same age as the Djadokhta Formation.

The santonian through paleogene record of Proteaceae in the southern South America - Antarctic peninsula region

1998 ◽  
Vol 11 (4) ◽  
pp. 373 ◽  
Author(s):  
Rosemary A. Askin ◽  
Alicia M. Baldoni
Keyword(s):  
South America ◽  
Antarctic Peninsula ◽  
Late Cretaceous ◽  
Fossil Record ◽  
Type Species ◽  
Pollen Record ◽  
South American ◽  
Southern South America ◽  
Nothofagus Forest ◽  
The Antarctic

Proteaceous plants were an important component of the high-latitude Late Cretaceous–Paleogene podocarpaceous conifer and Nothofagus forest vegetation growing in high-rainfall temperate conditions. In the southern South America–Antarctic Peninsula region the fossil record of the Proteaceae comprises pollen, leaves, fruits and wood with affinities to the extant subfamilies Grevilleoideae, Proteoideae, and possibly Carnarvonioideae and Persoonioideae. The oldest reported occurrences of Proteaceae in this region are in the middle–late Santonian of the Antarctic Peninsula and include pollen of Proteacidites subscabratus Couper, with the addition in the Campanian of other species of Proteacidites and Propylipollis, Cranwellipollis spp. and Peninsulapollis spp. Diversity of proteaceous pollen increased through the Campanian and Maastrichtian, reflecting the spread of Proteaceae along the Antarctic Peninsula and into South America. Both endemic species and species derived from the Australian region are represented. Compared to coeval Australian assemblages, however, proteaceous diversity remained relatively low. Interestingly, Beauprea-type species (Beaupreaidites spp., Peninsulapollis spp.) are common and varied in the Antarctic Peninsula from Campanian into the Eocene, yet the South American pollen record does not include these forms, except for rare Peninsulapollis gillii. Possibly drier conditions may have discouraged northward migration of this group. South American fossil proteaceous taxa are primarily related to Grevilleoideae, a trend that continues into the modern flora on that continent.

scholarly journals First Record of a living Platycopida (Crustacea, Ostracoda) from Antarcticwaters and a Discussion on Cytherella serratula (Brady, 1880)

Zootaxa ◽  
2008 ◽  
Vol 1866 (1) ◽  
pp. 349 ◽  
Author(s):  
SIMONE N. BRANDÃO
Keyword(s):  
New Species ◽  
Southern Ocean ◽  
Intraspecific Variation ◽  
Late Cretaceous ◽  
First Record ◽  
Review Of The Literature ◽  
Antarctic Region ◽  
Fossil Species ◽  
O2 Concentration ◽  
The Antarctic

Previous records of Platycopida (Ostracoda) from the Antarctic region of the Southern Ocean include only a few fossil species from the Late Cretaceous to the Palaeocene: Cytherelloidea megaspirocostata Majoran & Widmark, 1998, [sic] Cytherella serratula (Brady, 1880), plus seven species left in open nomenclature. The present study documents the first record of a living platycopid from the Antarctic region and describes Cytherella rwhatleyi sp. nov. as new. Comparison among specimens collected at stations 60° longitude and 10° of latitude apart from each other show that very little intraspecific variation in outline and ornamentation of the valves, as well as on the hemipenis is presented by this new species. Otherwise, clear differences on valve and hemipenis are observed between different species (herein, Jellinek & Swanson 2003). Review of the literature indicates that several species (with great differences in valve outline and ornamentation) have been erroneously assigned to Cytherella serratula (Brady, 1880) demonstrating that this so-called cosmopolitan taxon is in truth most probably restricted to bathyal depths of the Northwestern Atlantic. Finally, the abundances of Cytherella rwhatleyi sp. nov. in the samples studied herein (considering O2 concentration measurements) contradict the proposed relationship between Platycopida and O2 concentration in water masses (Whatley et al. 2003).

Late Cretaceous and Tertiary aporrhaid gastropods from the southern rim of the Pacific Ocean

1995 ◽  
Vol 69 (4) ◽  
pp. 692-702 ◽  
Author(s):  
William J. Zinsmeister ◽  
Miguel Griffin
Keyword(s):  
New Species ◽  
New Zealand ◽  
South America ◽  
Late Cretaceous ◽  
Late Eocene ◽  
Southern South America ◽  
Early Tertiary ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Early Cenozoic

The new subfamily Struthiopterinae is proposed for the aporrhaid gastropods occurring in the Late Cretaceous-early Tertiary Weddellian Province along the southern margin of the Pacific. The following genera are placed within the Struthiopterinae: Struthioptera Finlay and Marwick, 1937; Austroaporrhais n. gen.; and Struthiochenopus n. gen. The temporal and biogeographic distribution of members of Struthiopterinae show a similar pattern to other Southern Hemisphere groups of Late Cretaceous and early Cenozoic molluscs with initial disappearance from the western Australasia of the Weddellian Province by the Paleocene while surviving in Antarctica until the late Eocene and eventually disappearing in southern South America during the early Miocene.Also included in this paper is a reappraisal of the species assignable to these genera from Late Cretaceous and early Tertiary of New Zealand, Antarctica, and southern South America together with the description of five new species. The following new species of the Struthiopterinae are described: Austroaporrhais larseni n. sp., A. stilwelli n. sp., A. dorotensis n. sp., Struthiochenopus antarcticus n. sp., and S. philippii n. sp.

First record of the family Ringiculidae (Gastropoda) from the Middle Tertiary of Antarctica

1990 ◽  
Vol 64 (3) ◽  
pp. 373-376 ◽  
Author(s):  
William. J. Zinsmeister ◽  
Jeffrey D. Stilwell
Keyword(s):  
New Species ◽  
New Zealand ◽  
Late Cretaceous ◽  
First Record ◽  
Late Eocene ◽  
Late Mesozoic ◽  
Early Tertiary ◽  
The Pacific ◽  
The Family ◽  
A New Species

A new species of the late Mesozoic–Cenozoic family Ringiculidae (Ringicula (Ringicula) cockburnensis n. sp.) is described from basal glauconitic beds of late Eocene age of Cockburn Island, Antarctica, and is the first reported occurrence of the family Ringiculidae from the continent of Antarctica. Ringicula (R.) cockburnensis n. sp. most closely resembles R. castigata from the middle Oligocene Duntroonian Stage of New Zealand and provides further support for the strong provinciality (Weddellian Province) that existed along the southern margin of the Pacific during the Late Cretaceous and early Tertiary.

The genus Struthiochenopus (Gastropoda, Aporrhaidae): new Miocene records from southern Chile

2014 ◽  
Vol 88 (1) ◽  
pp. 152-159 ◽  
Author(s):  
Sven N. Nielsen ◽  
Alfonso Encinas
Keyword(s):  
New Species ◽  
South America ◽  
Antarctic Peninsula ◽  
Late Cretaceous ◽  
Early Miocene ◽  
Southern Chile ◽  
Southern South America ◽  
Marine Gastropod ◽  
The Antarctic

The marine gastropod genus Struthiochenopus appears first in the late Cretaceous of the Antarctic Peninsula. Until the Oligocene only one or two species were extant at the same time. This changed drastically in the early Miocene when at least three species were living coevally in southern South America. A possible fourth early Miocene species, Struthiochenopus sp., is known from Ipún Island, Chile, but its identification remains unclear. Another taxon, S. echtleri new species, described from Neogene deposits of Mocha Island, Chile, has no precise age available but it is likely the latest survivor of the genus.

A unifying lithostratigraphy of late Cretaceous–early Tertiary fore-arc volcanic sequences on Alexander Island, Antarctica

1997 ◽  
Vol 9 (2) ◽  
pp. 209-220 ◽  
Author(s):  
Joe J. McCarron
Keyword(s):  
Antarctic Peninsula ◽  
Late Cretaceous ◽  
Tectonic Setting ◽  
Volcanic Rocks ◽  
Magmatic Arc ◽  
Ridge Subduction ◽  
Volcanic Group ◽  
Early Tertiary ◽  
Plutonic Rocks ◽  
The Antarctic

Late Cretaceous–early Tertiary subduction-related fore-arc volcanic rocks are exposed in a north–south linear belt along the length of Alexander Island. The age and tectonic setting of these rocks is well understood; they are not considered to represent “normal” arc magmas but were generated in the fore-arc as a result of ridge subduction. Due to their distinct composition and mode of formation, they are no longer considered to be genetically related to the Antarctic Peninsula magmatic arc. They are therefore removed from the Antarctic Peninsula Volcanic Group and placed in a newly defined Alexander Island Volcanic Group. The group is made up of the Monteverdi, Staccato, Walton, Colbert, Elgar and Finlandia formations, which vary widely in lithology, facies and age. The Colbert and Elgar formations are subdivided into nine and three members respectively. Type localities, representative lithologies and age of each of the formations are discussed. The Staccato and Colbert Magmatic complexes are defined to include volcanic and plutonic rocks that are considered to be coeval. The Rouen Intrusive complex combines the plutonic rocks from the Rouen Mountains and Rothschild Island on the basis of age and chemistry.

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