Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Phylogeny and biogeography of pholadid bivalve Barnea [Anchomasa] with considerations on the phylogeny of Pholadoidea

100%
Monari S.
Acta Palaeontologica Polonica
|
2009
|
tom 54
|
nr 2
315-335
The paper examines the systematics, phylogeny and biogeographical history of Barnea (Anchomasa), which is one of the most abundant and diversified of modern pholadid bivalves. The range of morphology of its distinctive characters and comparisons with other pholadoidean taxa are described in detail. An extensive cladistic analysis based on morphological characters at genus and subgenus levels allowed the inclusion of B. (Anchomasa) into the phylogeny of Pholadoidea and the establishment of its most appropriate taxonomic position. The analysis confirms that Barnea s.s. and B. (Umitakea) are its closest relatives and that the morphological similarities to other taxa are mainly due to plesiomorphies. The fossil record and the data on the present−day distribution contributed to trace the biogeographical history of B. (Anchomasa). The present−day biogeography is marked by the disjunct distribution of species. Species are distributed mainly either along the Atlantic and Pacific coasts of the American continent (American group) or in the Indo−West Pacific region (Indo−West Pacific group). Both these groups have distinct morphological features and biogeographical structures. The fossil record and the known geodynamic scenario suggest a relationship of direct derivation between the Indo−West Pacific group and a stock of north−eastern Atlantic to Paratethyan species. This reflects a vicariant event related to the closure of the connection between western Tethys and the Indian Ocean in the middle Miocene. The American group presumably arose from the European stock during the Late Pliocene by dispersal towards the eastern coasts of North America and rapid southward diffusion. A relative differentiation within the American group is probably related to the last phases of emergence of the Panama Isthmus. The cladistic analysis also gives suggestions for the reconstruction of the phylogeny of the superfamily Pholadoidea. It confirms the interpretation of several characters sustained by previous authors. However, it also shows remarkable differences to the previous taxonomic arrangements. Pholadinae includes only taxa having the protoplax and it appears to be the sister−group of a major clade composed mainly of two groups, namely Martesiinae– Jouannetiinae and Xylophagainae–Teredinidae. The Martesiinae are paraphyletic whereas the obligate wood−boring Xylophagainae and Teredinidae form a well−supported monophyletic group.
2
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

The Jurassic pleurotomarioidean gastropod Laevitomaria and its palaeobiogeographical history

51%
Gatto R., Monari S., Szabo J., Conti M. A.
Acta Palaeontologica Polonica
|
2015
|
tom 60
|
nr 1
The genus Laevitomaria is reviewed and its palaeobiogeographical history is reconstructed based on the re-examination of its type species L. problematica, the study of material stored at the National Natural History Museum of Luxembourg, and an extensive review of the literature. The systematic study allows ascribing to Laevitomaria a number of Jurassic species from the western European region formerly included in other pleurotomariid genera. The following new combinations are proposed: Laevitomaria allionta, L. amyntas, L. angulba, L. asurai, L. daityai, L. fasciata, L. gyroplata, L. isarensis, L. joannis, L. repeliniana, L. stoddarti, L. subplatyspira, and L. zonata. The genus, which was once considered as endemic of the central part of the western Tethys, shows an evolutionary and palaeogeographical history considerably more complex than previously assumed. It first appeared in the Late Sinemurian in the northern belt of the central western Tethys involved in the Neotethyan rifting, where it experienced a first radiation followed by an abrupt decline of diversity in the Toarcian. Species diversity increased again during Toarcian–Aalenian times in the southernmost part of western European shelf and a major radiation occurred during the Middle Aalenian to Early Bajocian in the northern Paris Basin and southern England. After a latest Bajocian collapse of diversity, Laevitomaria disappeared from both the central part of western Tethys and the European shelf. In the Bathonian, the genus appeared in the south-eastern margin of the Tethys where it lasted until the Oxfordian.
3
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Earliest Jurassic patellogastropod, vetigastropod, and neritimorph gastropods from Luxembourg with considerations on the Triassic–Jurassic faunal turnover

51%
Monari S., Valentini M., Conti M. A.
Acta Palaeontologica Polonica
|
2011
|
tom 56
|
nr 2
The Hettangian to earliest Sinemurian Vetigastropoda, Patellogastropoda, and Neritimorpha housed in the National Museum of Natural History of Luxembourg are studied. Most of the species comes from the Luxembourg Sandstone Formation. This deposit formed along the southern margin of the London−Brabant−Ardennes Landmass, in a region that during the earliest Jurassic constituted a seaway connecting the Paris Basin with the epicontinental seas of the Netherlands and northern Germany. The systematic analysis revealed high diversity of the studied fauna; we identified twenty−two species, eleven genera, nine families, and six superfamilies. A new genus, Meiersia gen. nov., and three new species, Anodomaria schroederi sp. nov., Meiersia disarmata sp. nov., and Spirocirrus weisi sp. nov. are described. The fauna is dominated by pleurotomarioideans representing the genera Ptychomphalus, Pleurotomaria, and Trochotoma, and by the patellogastropod genus Scurriopsis both in number of species and specimens. The neritimorph genus Neridomus is also well represented. Among the accessory taxa, Anodomaria and Spirocirrusfirst appeared in the Late Hettangian of the Luxembourg area. Most of these genera show a species radiation in the Early Jurassic and are distributed over the western European epicontinental shelf, probably favoured by an east to west marine transgression which influenced wide areas from the basins of the northern Germany to the Paris Basin through the Luxembourg seaway. The evolutionary and palaeobiogeographical data demonstrate that this radiation was already considerably advanced in the Late Hettangian. This suggests that the recovery of the gastropod diversity after the end−Triassic crisis was relatively fast in western Europe.
4
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

A new caenogastropod from the upper Rhaetian of Lombardy: Palaeobiogeographical history and implications for the Early Jurassic gastropod recovery

51%
Pieroni V., Monari S., Todd J. A.
Acta Palaeontologica Polonica
|
2021
|
tom 66
|
nr 1
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.