Entity

Time filter

Source Type

Twardogóra, Poland

Majewski W.,Instytut Paleobiologii PAN
Polish Polar Research | Year: 2010

After several years of research, the foraminiferal fauna of Admiralty Bay (King George Island, South Shetland Islands) has become the most studied fiord in West Antarctica with respect to foraminifera. As such, it provides actualistic data for better understanding of paleoenvironmental records from this dynamically changing area. Over a few years, the bay was systematically sampled down to 520 m water depth, for multichambered and monothalamous benthic foraminifera, including softwalled allogromiids often overlooked in former studies. Altogether, 138 taxa were identified, and three new taxa described. This paper aims to integrate these results, put them into a broader perspective, and supplement them with information that was not presented to date. Most notably, a record of the vertical distribution of Rose Bengal stained foraminifera below the sediment surface and the proportions of soft and robustlytestate forms at different sites are described. Source


Majewski W.,Instytut Paleobiologii PAN
Polish Polar Research | Year: 2013

Twenty one core tops from the central part of Pine Island Bay and nearby Ferrero Bay were collected in early 2010. They originate from a poorly studied area of the Amundsen Sea influenced at greater depths by relatively warm Circumpolar Deep Water. Almost all samples came from water-depths between 550 and 900 m and yield benthic foraminiferal assemblages of moderate variability with a significant decrease in calcareous forms with increasing water-depth. In total, 93 benthic taxa, belonging to 71 genera, are identified at the species level. They share a greater percentage of common species with the Ross Sea than with South Shetland Islands, most likely due to stronger climatic dissimilarity with the latter. Interestingly, the assemblages from Pine Island Bay, share the greatest numbers of taxa with assemblages described from Lützow-Holm Bay in East Antarctica, where the influence of Circumpolar Deep Water has been also recognized. Source


Roniewicz E.,Instytut Paleobiologii PAN
Acta Palaeontologica Polonica | Year: 2011

The first description of early Norian coral fauna from the Northern Calcareous Alps (Dachstein Plateau and Gosaukamm), Austria, is presented: 31 scleractinian species from 24 genera (including three corals not formally determined), and three hexanthiniarian species belonging to two genera. The stratigraphical position of the main part of the fauna discovered in the South Dachstein Plateau at the Feisterscharte is determined by means of the conodont Epigondolella quadrata (Lacian 1); single finds are from the horizons with Epigondolella triangularis and Norigondolella navicula (Lacian 3), and one close to the horizon with Epigondolella cf. multidentata (Alaunian 1). Rare corals from the Gosaukamm are from the Lacian 1 and Alaunian. Five species are described as new: Retiophyllia vesicularis, Retiophyllia aranea, Margarosmilia adhios, Hydrasmilia laciana; one new genus and species from the family Coryphylliidae, Margarogyra hirsuta; one new genus and species, Thamnasterites astreoides, cannot be assigned to a family. Two hexanthiniarian species, Pachysolenia cylindrica and Pachydendron microthallos, known exclusively from the Tethyan lower Norian, represent stratigraphically valuable species. A regularly porous coral from the family Microsolenidae, Eocomoseris, which up to now has only been known from the Jurassic and Cretaceous, is here identified from the Triassic strata (originally described as Spongiomorpha [Hexastylopsis] ramosa). Predominant taxa show solitary and phaceloid (pseudocolonial) growth forms and an epithecal wall; pennules-bearing corals are common. Carnian genera and genera typical of the Lacian and Lacian-early Alaunian prevail; a hydrozoan genus Cassianastraea has also been encountered as well as a scleractiamorph coral, Furcophyllia septafindens). The faunal composition contrasts with that of well known late Norian-Rhaetian ones, the difference being observed not only at the generic but also at the family level. The post-early Norian change in coral spectrum documents the turnover of the coral fauna preceding that at the Triassic/Jurassic boundary. Source


Dzik J.,Instytut Paleobiologii PAN
Bollettino della Societa Paleontologica Italiana | Year: 2011

The morphological series composed of large xenusiids of the Chengjiang fauna of China and the basal anomalocaridids Pambdelurion and Kerygmachela from the Sirius Passet fauna of Greenland is supplemented with another xenusiid lobopodian, Siberion lenaicus gen. et sp. nov., from the Early Cambrian Sinsk Formation of central Siberia. Reduction and ventral bending of the proboscis in Siberion and the Chengjiang Megadictyon and Jianshanopodia may be a synapomorphy uniting these representatives with the anomalocaridids. Throughout the series, the raptorial appendages became larger and more sclerotised, while the gill-like structures on the trunk appendages were transformed from their originally tubular shape into a pinnate form and may eventually have given rise to the wide anomalocaridid flaps. Such a tendency can be rooted in the Aysheaia-like xenusians, that have raptorial appendages associated with a prominent proboscis. This results in a scenario of almost complete transition from early lobopodians to ancestral arthropods within the xenusian-anomalocaridid segment of the phylogenetic tree. Source


Colonies of boring ctenostome bryozoans and microborings of "fungi" that occur in the Early Devonian (Lochkovian, ∼416 Ma) of Podolia, western Ukraine, have soft-tissue preserved by phosphatization. These comprise exceptional three-dimensional body walls of feeding zooids with probable parietal muscles inserted on the cystid wall, and setigerous collars twisted within the vestibulum. The presence of collars in this Early Devonian ctenostomes proves the existence of this feature for more than 416 Ma of ctenostome evolution. Phosphatized remains of the zooid walls are interpreted as relicts of the originally chitinous cystid walls. This is the first record of soft-tissue fossilization in a boring bryozoan. The presence of cavities (specialized heterozooids), empty or filled with laminated calcium phosphate, is also documented in bryozoans for the first time. These cavities are interpreted as "store-rooms" in which the bryozoans accumulated nutrients. The new taxon, Podoliaporu doroshevi gen. et sp. nov. is described. In additional, phosphatised fungi-like endoliths co-occur with bryozoans. Copyright © 2012. Source

Discover hidden collaborations