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Wyszukujesz frazę "ammonoidea" wg kryterium: Temat


Wyświetlanie 1-5 z 5
Tytuł:
Ammonite faunal dynamics across bio-events during the mid- and Late Cretaceous along the Russian Pacific coast
Autorzy:
Jagt-Yazykova, E.A.
Powiązania:
https://bibliotekanauki.pl/articles/22657.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
ammonite
fauna dynamics
Late Cretaceous
Cretaceous
Russian coast
Pacific coast
Ammonoidea
evolution
Opis:
The present paper focuses on the evolutionary dynamics of ammonites from sections along the Russian Pacific coast during the midand Late Cretaceous. Changes in ammonite diversity (i.e., disappearance [extinction or emigration], appearance [origination or immigration], and total number of species present) constitute the basis for the identification of the main bio−events. The regional diversity curve reflects all global mass extinctions, faunal turnovers, and radiations. In the case of the Pacific coastal regions, such bio−events (which are comparatively easily recognised and have been described in detail), rather than first or last appearance datums of index species, should be used for global correlation. This is because of the high degree of endemism and provinciality of Cretaceous macrofaunas from the Pacific region in general and of ammonites in particular.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Barremian heteromorph ammonite Dissimilites from northern Italy: Taxonomy and evolutionary implications
Autorzy:
Lukeneder, A.
Lukeneder, S.
Powiązania:
https://bibliotekanauki.pl/articles/22570.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
Ammonoidea
Acrioceratidae
Barremian
Cretaceous
heteromorph ammonite
Dissimilites
Italy
taxonomy
evolution
Alps Mountains
Opis:
A new acrioceratid ammonite, Dissimilites intermedius sp. nov., from the Barremian (Lower Cretaceous) of the Puez area (Dolomites, northern Italy) is described. Dissimilites intermedius sp. nov. is an intermediate form between D. dissimilis and D. trinodosum. The new species combines the ribbing style of D. dissimilis (bifurcating with intercalating single ribs) with the tuberculation style of D. trinodosum (trituberculation on entire shell). The shallow-helical spire, entirely comprising single ribs intercalated by trituberculated main ribs, is similar to the one of the assumed ancestor Acrioceras, whereas the increasing curvation of the younger forms resembles similar patterns observed in the descendant Toxoceratoides. These characters support the hypothesis of a direct evolutionary lineage from Acrioceras via Dissimilites to Toxoceratoides. D. intermedius sp. nov. ranges from the upper Lower Barremian (Moutoniceras moutonianum Zone) to the lower Upper Barremian (Toxancyloceras vandenheckii Zone). The new species allows to better understand the evolution of the genus Dissimilites. The genus appears within the Nicklesia pulchella Zone represented by D. duboise, which most likely evolved into D. dissimilis. In the Kotetishvilia compressissima Zone, two morphological forms developed: smaller forms very similar to Acrioceras and forms with very long shaft and juvenile spire like in D. intermedius sp. nov. The latter most likely gave rise to D. subalternatus and D. trinodosum in the M. moutonianum Zone, forms which were probably ancestral to the genus Toxoceratoides.
Źródło:
Acta Palaeontologica Polonica; 2014, 59, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Devonian pearls and ammonoid-endoparasite co-evolution
Autorzy:
De Baets, K.
Klug, C.
Korn, D.
Powiązania:
https://bibliotekanauki.pl/articles/23478.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Algeria
Ammonoidea
Devonian
Germany
Morocco
Trematoda
paleontology
parasite
pearl
evolution
terminology
distribution
ammonoid
endoparasite
Opis:
Raised shell projections on the inner shell walls that form pits on the internal moulds of Devonian ammonoids have been known for several decades. New specimens from Morocco reveal novel details of these structures; most, if not all, of which consist of a capsule of ammonoid shell that covers tiny tubes attached to the outer (= lateral or ventral) shell wall from the inside. In accordance with comparable Recent occurrences of similar structures in molluscs, we use the term “pearls” for these structures and the pits they form on the internal moulds. The nature of these encapsulated tubes is described and discussed. Because of the presence of these tubes inside the pearls, pearl arrangement, and their similarity to Recent mollusc occurrences, the tubes are interpreted as traces of parasitoses. The pearls and pits were grouped into five types based on differences in morphology, size, and arrangement. Then, having used these traits to perform a simple cladistic analysis, the resulting cladogram was compared to the phylogeny of ammonoids. Based on this comparison, it appears likely that the parasites underwent a co−evolution with the ammonoids, which lasted 10 to 15 Ma. Patterns of evolutionary events include co−speciation, “drowning on arrival” (end of parasite lineage near base of a new host clade), and “missing the boat” (parasite lineage does not adapt to a new host clade, thus not evolving a new parasite clade). Because of the lack of fossilised soft tissue, only speculations can be made about the systematic affiliation of the parasites, their life−cycle, infection strategy, and ecological framework. Some co−occurring bivalves also have pits reminiscent to structures caused by trematodes in Recent forms. Based on the available information, the tubes are interpreted as artefacts of trematode infestations, which, if correct, would extend the fossil record of parasitic trematodes into the Early Devonian.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrodynamically controlled anagenetic evolution of Famennian goniatites from Poland
Autorzy:
Niechwedowicz, M
Trammer, J.
Powiązania:
https://bibliotekanauki.pl/articles/22390.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
environment change
Famennian
hydrodynamics
Ammonoidea
Polska
Devonian
evolution
Holy Cross Mountains
Tornoceratidae
paleontology
fossil animal
ammonoid
Opis:
This paper reports on the evolution of ammonoids belonging to the family Tornoceratidae from the Devonian of Janczyce in the Holy Cross Mountains, Poland. Steady and gradual changes in conch morphology of the goniatite lineage Phoenixites frechi–Tornoceras subacutum–T. sublentiforme occurred in concert with water shallowing during the deposition of the Lower Famennian cephalopod limestone. Biometric analysis of ammonoid conch and facies analysis of the cephalopod limestones have been applied to assess the possible relationship between shell geometry and environmental changes. Results show that ratios of whorl width / diameter as well as whorl width / whorl height decreased, while distance from the venter to the greatest whorl width / diameter increased with time, thereby reducing hydrodynamic drag of the shells, probably in response to increasing water turbulence. The interpretation presented here is in agreement with similar cases from the literature. However, this kind of environmentally controlled evolution has hitherto been recognized only in Jurassic and Cretaceous ammonoids. Conch morphology may be considered as an indicator of palaeobathymetry.
Źródło:
Acta Palaeontologica Polonica; 2007, 52, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emergence and collapse of the Frasnian conodont and ammonoid communities in the Holy Cross Mountains, Poland
Autorzy:
Dzik, J
Powiązania:
https://bibliotekanauki.pl/articles/21673.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Ammonoidea
paleobiology
Conodonta
Polska
collapse
population variability
conodont
community
Frasnian
change
Devonian
evolution
Holy Cross Mountains
paleontology
ammonoid
Opis:
The dominant factor in faunal succession of conodonts in the Frasnian of Poland is the apparent immigration of species originating allopatrically in other regions. Each immigration event usually changes the population variability of a local species (character displacement). Only a few lineages show their phyletic evolution within the studied area. Attempts to distinguish conodont species on the basis of platform element shape failed in some of the latest Frasnian palmatolepidids. Even at the apparatus−based generic level, certain ramiform elements of the apparatus appear much more diagnostic than the platforms. Correlative value of the late Frasnian palmatolepidids of unknown apparatus structure is thus questionable. The evolution of platform elements in Ancyrodella offers a more solid basis for age determination although their great population variability makes resolution rather low and requires the population approach. The panderodontids Belodella(?) tenuiserrata sp., B. minutidentata sp. nov., B. robustidentata sp. nov., prioniodontid Icriodus kielcensis sp. nov., enigmatic monospecific Playfordiidae fam. nov., prioniodinids Dyminodina planidentata gen. et sp. nov., D. anterodenticulata sp. nov., D. kovalensis sp. nov., Pluckidina kielcensis gen. et sp. nov., P. slupiensis sp. nov., P. robustipegmata sp. nov., and P. lagoviensis sp. nov., derived polygnathid Avignathus bifurcatus sp. nov., probably secondarily simplified polygnathid Nicollidina gen. nov., and palmatolepidids Kielcelepis gen. nov., Lagovilepis gen. nov. and Klapperilepis gen. nov. are proposed.
Źródło:
Acta Palaeontologica Polonica; 2002, 47, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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