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| Registros recuperados: 10 | |
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| Janssen, A.W.. |
| A borehole was drilled at Rotterdam in 1955 as a demonstration during the E55 exhibition. Holoplanktonic molluscs (pteropods) were found to be present in the interval 504.5-655.0 m below rotary table (= RT). The upper sample of Middle Eocene (Lutetian) age yielded just a few unidentifiable limacinids. The section between 507.5-607.0 m, of Early Eocene (Ypresian) age, yielded poorly preserved pteropods and demonstrated that the complete interval belongs to pteropod zone 9. Apart from the most abundant species, Camptoceratops priscus, which is the index taxon of pteropod zone 9, the section yielded Heliconoides mercinensis and Limacina taylori, which are known to accompany the index species. Two further limacinid species are described as new to science, viz.... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Mollusca; Gastropoda; Thecosomata; Pteropods; The Netherlands; Eocene; Ypresian; Biostratigraphy; 38.22. |
| Ano: 2010 |
URL: http://www.repository.naturalis.nl/record/361978 |
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| Janssen, A.W.. |
| Fifteen samples taken from interbedded sandstone, siltstone and claystone of Pliocene age, underlying the Bolinao Limestone, at the localities Anda, Roxas and Tiep (Pangasinan, Luzon, Philippines), were analysed for holoplanktonic gastropods; they have yielded 50 species (16 Heteropoda, one Janthinidae, and 33 Pteropoda, the latter consisting of 30 Euthecosomata, two Pseudothecosomata and one Gymnosomata). Faunal diversity between the localities sampled is restricted and explained by differences in sample size and/or preservation. The time interval represented by all samples taken together is postulated to have been brief. Fifteen new taxa (= 30% of the total number of encountered holoplanktonic molluscan species) are erected; Atlanta lingayanensis sp.... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Mollusca; Pliocene; Philippines; Taxonomy; New species; 42.73; 38.22. |
| Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/314194 |
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| Janssen, A.W.. |
| The author gives an enumeration of the molluscan species of the 'Twistringer Schichten" (Miocene, Northern Germany). Many of the species listed here are new to this particular facies of the Miocene of the North Sea Basin. The material studied was collected in the claypits of the brickworks at Twistringen and Woltrup. A short stratigraphical review precedes the list of species. In the systematical part nomenclatural notes and descriptions of seventeen new species and subspecies are brought together. |
| Tipo: Article / Letter to the editor |
Palavras-chave: 38.22. |
| Ano: 1972 |
URL: http://www.repository.naturalis.nl/record/317480 |
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| Janssen, A.W.; Slik, L. van der. |
| Two new species and a new subspecies of the Astartidae (Mollusca, Bivalvia) are described from reworked shell material of beaches and estuaries in the Province of Zeeland, The Netherlands. Nomenclatural notes concerning some other species of the same family are added. Furthermore an attempt is made to demonstrate the phylogenetical development of the Astarte (Isocrassina) fusca and the A. (I.) omalii group from the younger Caenozoic (Miocene to Quaternary) of the North Sea Basin. |
| Tipo: Article / Letter to the editor |
Palavras-chave: 38.22. |
| Ano: 1974 |
URL: http://www.repository.naturalis.nl/record/317532 |
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| Janssen, A.W.; Muller, P.. |
| Reworked phosphoritic concretions from the base of the Diest Sands (Miocene) at Ramsel (Belgium) yield many magnificent crabs and molluscs in mould preservation. Two species of crabs are present, viz. Mursia lienharti (Bachmayer, 1961) and Tasadia carniolica (Bittner, 1884), Tasadia being a new genus. The palaeoecology of the decapod fauna is discussed and compared with Paratethyan occurrences. The age of the fauna in the concretions as indicated by the mollusc fauna is Middle Miocene, Hemmoorian, youngest Oxlundian. A similar fauna, also in reworked concretions, is known from the base of the Deurne Sands at Borgerhout (Antwerpen city area). A new coleoid cephalopod species, Spirulirostra baetensi sp. nov., is described. The European Spirulirostra and... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 38.22. |
| Ano: 1984 |
URL: http://www.repository.naturalis.nl/record/317400 |
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| Janssen, A.W.. |
| All Tertiary euthecosomatous gastropods from the Australian continent known to the author are described. The species introduced by Ralph Tate (1887) are revised. Altogether 18 species are discussed. A new genus, Spoelia, and five new species, viz. Limacina curryi, L. lunata, L. tatei, Spoelia torquayensis and Vaginella victoriae, are introduced. Potential tools in the Australian pteropod fauna for a future biostratigraphical zonation and for long distance correlations are indicated. In an annex Vaginella sannicola sp. nov. is introduced for specimens from the Miocene of Gargano, Italy, which were incorrectly identified as V. eligmostoma Tate by d'Alessandro & Robba, 1980. |
| Tipo: Article / Letter to the editor |
Palavras-chave: 38.22. |
| Ano: 1989 |
URL: http://www.repository.naturalis.nl/record/317441 |
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| Cahuzac, B.; Janssen, A.W.. |
| Holoplanktonic Mollusca collected from c. 60 localities in Cenozoic (Eocene-Ypresian to Miocene-Serravallian) rocks of the Aquitaine Basin (southwest France) are represented by 75 taxa: five supposed Heteropoda (Pterotracheoidea) and 70 Pteropoda (69 Thecosomata, one Gymnosomata). All Heteropoda and 19 species of the Pteropoda had to be included in open nomenclature or with a query. Twelve species of pteropods are described as new to science: Heliconoides daguini sp. nov., H. merlei sp. nov., H. pyrenaica sp. nov. and Limacina? vegrandis sp. nov. from the Ypresian; Creseis antoni sp. nov. and Vaginella gaasensis sp. nov. from the Rupelian; Clio lozoueti sp. nov. and Clio vasconiensis sp. nov. from the Chattian; Diacrolinia cluzaudi sp. nov., from the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Heteropoda; Pteropoda; Taxonomy; Biostratigraphy; New species; Aquitaine Basin; Eocene-Miocene; 38.22; 42.73. |
| Ano: 2010 |
URL: http://www.repository.naturalis.nl/record/344594 |
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| Janssen, A.W.; Zorn, I.. |
| In the early thirties the late Polish palaeontologist Wilhelm Krach started the publication of a long series of papers on the mollusc faunas and the biostratigraphy of the Tertiary deposits in Poland, predominantly focusing on the Miocene of the Carpathian Foredeep. In several of these papers holoplanktonic molluscs ('pteropods') are mentioned. Gradually Krach realised the potential value of these organisms in regional and interregional biostratigraphy, resulting in a special paper on the subject, published in 1981. In the present paper a substantial part of Krach's pteropod material, housed in the Institute of Geological Sciences at Kraków, is systematically revised and biostratigraphically interpreted according to modern standards and in accordance with... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 38.22. |
| Ano: 1992 |
URL: http://www.repository.naturalis.nl/record/317304 |
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| Janssen, A.W.. |
| From the recently discovered mollusc fauna of Winterswijk-Miste (The Netherlands, province of Gelderland) nineteen species of Cancellariidae are described; one of these is supposed to be derived from Chattian sediments. The Miocene (Hemmoorian) age of this fauna is supported by the cancellariid species. Among the eighteen species collected in situ four species and a subspecies appeared to be new, viz. Trigonostoma mistense, T. barnardi, T. lindeni, T. pouwi, and T. geslini josephinae. Another new species, Sveltia gliberti, is described from the Edegem Sands in Belgium. Furthermore, a new subgenus, Misteia, is introduced within the genus Trigonostoma for T. planispirum Nyst (type species), T. mistense sp. nov. and T. mutinense (Foresti) |
| Tipo: Article / Letter to the editor |
Palavras-chave: 38.22. |
| Ano: 1984 |
URL: http://www.repository.naturalis.nl/record/317474 |
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| Registros recuperados: 10 | |
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