Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "functional morphology" wg kryterium: Temat


Tytuł:
Ecomorphological and taphonomic gradients in clypeasteroid-dominated echinoid assemblages along a mixed siliciclastic-carbonate shelf from the early Miocene of northern Sardinia, Italy
Autorzy:
MANCOSU, ANDREA
NEBELSICK, JAMES H.
Tematy:
echinoidea
taphonomy
functional morphology
palaeoecology
miocene
sardinia
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:
https://bibliotekanauki.pl/articles/945625.pdf  Link otwiera się w nowym oknie
Opis:
Clypeasteroid echinoids are widespread and abundant within Miocene sedimentary sequences of the Mediterranean area within both siliciclastic and carbonate deposits. Herein, three clypeasteroid-dominated echinoid assemblages from the mixed siliciclastic-carbonate succession of the Mores Formation (lower Miocene) cropping out within the Porto Torres Basin (northern Sardinia) are described. These assemblages were compared to previously described clypeasteroid-bearing deposits from the Miocene of northern Sardinia with the purpose of investigating their palaeoecology and taphonomy along a shelf gradient. These goals are accomplished by various methods including (i) logging sedimentary facies, (ii) analysing the functional morphology of sea urchin skeletons, (iii) comparing the relative abundance of taxa and taphonomic features, and (iv) studying associated fauna, flora, and trace fossils. The clypeasteroid-bearing deposits differ greatly with respect to echinoid diversity, accompanying fauna and flora, sedimentological signatures, and taphonomic features. They also show variations in depositional environments and the mechanism of formation of the deposits. Three different shelf settings are distinguished: littoral, inner sublittoral, and outer sublittoral environments. Furthermore, an ecomorphological gradient along the shelf is recognized with respect to echinoid taxa and their morphologies. This gradient ranges from shallow water to a moderately deep shelf and is interpreted with respect to both abiotic and biotic factors as well as the taphonomy of the echinoid tests.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Platy corals from the Middle Triassic of Upper Silesia, Poland : implications for photosymbiosis in the first scleractinians
Autorzy:
Kołodziej, Bogusław
Łabaj, Marcelina A.
Szulc, Joachim
Morycowa, Elżbieta
Salamon, Klaudiusz
Opis:
Coral patch reefs from Middle Triassic (upper Pelsonian-lower Illyrian) strata in the Upper Silesia region of southern Poland (Germanic domain of the Peri-Tethys) are rare examples of the first scleractinian buildups. The shallowing-upward succession in the Tarnów Opolski quarry records a transition from sponge to coral patch reefs interbedded with bioclastic limestones. Coral pillarstones built by thin, branching Volzeia szulci are succeeded by platy Pamiroseris silesiaca constructing two platestone layers, each up to 50 cm thick. Serial sections through platestones revealed flat to undulose growth form of P. silesiaca. The maximum observable dimension of the coral plates is 24 cm wide (typically up to 12 cm), while thickness of most plates is 1-1.5 cm. Coral plates are interlayered with crinoidal wacke- to packstone and microbialites, which are locally important component of the platestone. Platy corals grew in a shallow, turbid-water environment with changing, but dominantly moderate hydrodynamics. Net sedimentation was low, as indicated by the epibionts encrusted to the undersides of the coral plates, and locally common microbial fabrics. Growth-interruptions of P. silesiaca record events of storm-induced sediment input and resuspension of carbonate mud. Based on the euphotic floor model, the flattened morphology of P. silesiaca is interpreted as an optimal growth form in a turbid, low-light environment. Platy scleractinian assemblages from Silesia are the oldest occurrences of this ecological coral group (mostly representing deeper, mesophotic habitats) and support the hypothesis that some of the earliest scleractinians had photosymbionts like modern zooxanthellae.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
New findings reveal that the Middle Triassic ichthyosaur Mixosaurus cornalianus is the oldest amniote with a dorsal fin
Autorzy:
Renesto, S.
Dal Sasso, C.
Fogliazza, F.
Ragni, C.
Tematy:
Ichthyosauria
Mixosauridae
soft tissue preservation
functional morphology
Mesozoic
Italy
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:
https://bibliotekanauki.pl/articles/2082209.pdf  Link otwiera się w nowym oknie
Opis:
Two excellently preserved specimens of Mixosaurus cornalianus from the Anisian layers of the Middle Triassic Formazione di Besano, with soft parts associated with well-articulated skeletal elements, revealed the presence in this species of a dorsal fin and of a well-developed, triangular dorsal lobe of the caudal fin, both stiffened by an array of fibre bundles, as in Jurassic fast-swimming ichthyosaurs. This finding testifies that efficient swimming exaptations were already present in some Middle Triassic ichthyosaurs. Mixosaurus is then the oldest amniote so far known that developed a dorsal fin. The preservation of the fin shapes, scaleless skin, and three-dimensional dermal fibres is remarkable, allowing observation of their microstructure, and ruling out any artefactual interpretation. Stomach contents indicate that both specimens preyed upon cephalopods and small fishes. An internal organ, possibly a tract of the intestine, is also preserved in one specimen, which represents the first documented case in the ichthyosaurs of the Besano Formation, and a rarity in the fossil record of the clade.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oviraptorosaur tail forms and functions
Autorzy:
Persons,IV, W.S.
Currie, P.J.
Norell, M.A.
Tematy:
Dinosauria
paleozoology
Theropoda
Oviraptorosauria
oviraptorosaur
pygostyle
caudal musculature
functional morphology
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:
https://bibliotekanauki.pl/articles/945893.pdf  Link otwiera się w nowym oknie
Opis:
Oviraptorosaur caudal osteology is unique among theropods and is characterized by posteriorly persistent and exceptionally wide transverse processes, anteroposteriorly short centra, and a high degree of flexibility across the pre-pygostyle vertebral series. Three-dimensional digital muscle reconstructions reveal that, while oviraptorosaur tails were reduced in length relative to the tails of other theropods, they were muscularly robust. Despite overall caudal length reduction, the relative size of the M. caudofemoralis in most oviraptorosaurs was comparable with those of other non-avian theropods. The discovery of a second Nomingia specimen with a pygostyle confirms that the fused terminal vertebrae of the type specimen were not an abnormality. New evidence shows that pygostyles were also present in the oviraptorosaurs Citipati and Conchoraptor. Based on the observed osteological morphology and inferred muscle morphology, along with the recognition that many members of the group probably sported broad tail-feather fans, it is postulated that oviraptorosaur tails were uniquely adapted to serve as dynamic intraspecific display structures. Similarities, including a reduced vertebral series and a terminal pygostyle, between the tails of oviraptorosaurs and the tails of theropods widely accepted as basal members of the Avialae, appear to be convergences.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aszulcicrinus, a new genus of the Triassic crinoid family Dadocrinidae (Articulata; Encrinida) from Poland
Autorzy:
Hagdorn, Hans
Tematy:
Crinoidea
Middle Triassic
early Anisian
Upper Silesia
functional morphology
taphonomy
Pokaż więcej
Wydawca:
Polskie Towarzystwo Geologiczne
Powiązania:
https://bibliotekanauki.pl/articles/1836258.pdf  Link otwiera się w nowym oknie
Opis:
The new genus and species Aszulcicrinus pentebrachiatus of the family Dadocrinidae from the ear-ly Middle Triassic Lower Gogolin Formation of Upper Silesia Upland is described. In contrast to Dadocrinus, the second primibrachial of Aszulcicrinus is not axillary for articulation with two arms but articulates with a third primibrachial and the first pinnule. This character results in five unbranched arms, which is unique in the order Encrinida. The significance of this character is discussed and paedomorphic or ecophenotypic explanations are excluded. The presence of only five unbranched arms predominates through the ontogeneny of Aszulcicrinus from early postlarval to adult stage. Within the family Dadocrinidae (Aszulcicrinus - Dadocrinus - Carnallicrinus), a phylogenetic trend towards size increase coincident with increasing arm number and denser pinnulation is inter-preted as an improvement in filter-feeding efficiency. The sedimentological and taphonomic setting of the obru-tional conservation lagerstätte of the type locality is described.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carnassiform notches improve the functional efficiency of bat molar shearing crests
Autorzy:
Czaplewski, Nicholas J.
Baker, Charles G.
Tematy:
Mammalia
Chiroptera
dental morphology
functional morphology
functional design
molars
talonid cests
shearing blades
bio-engineering
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:
https://bibliotekanauki.pl/articles/2216220.pdf  Link otwiera się w nowym oknie
Opis:
We surveyed molar surface morphology of bats of 281 extant and extinct species in 5 archaic and 19 extant families using scanning microscopy. We note the occurrence of structural features on talonid crests, the cristid obliqua, postcristid, and entocristid, and their absence in upper molars, even of the same species having them on lowers. We term the structures “carnassiform notches” (CN) for their resemblance to similar features on the carnassial teeth of carnivorans. A CN consists of a small cleft in the edge of a talonid shearing crest accompanied by an adjacent “accessory trough” on the basinward side of the notch. The CN occur in bats with tribosphenic molar morphology and insectivorous or insectivorous–omnivorous dietary habits. Of 19 extant families examined, eight include members that possess lower molars with a CN in at least the cristid obliqua: Megadermatidae, Nycteridae, Mystacinidae, Furipteridae, Thyropteridae, Phyllostomidae, Natalidae, and Vespertilionidae (Murininae and Kerivoulinae only). An extinct genus of Hipposideridae, Vaylatsia, shows CN although extant hipposiderids do not. In extinct families for which lower molar fossils are available, notches were not recognized on the talonids, indicating the condition is not plesiomorphic for bats and probably evolved convergently in different lineages. Where present, the CN or troughs are morphologically consistent within a family, and might serve in some cases as characters supporting phylogenetic analyses and clade diagnoses. CN and accessory troughs probably increase the functional efficiency at sectioning chitin by increasing the effective length of a crest while maintaining the same cusp-to-cusp distance and precise occlusal relationships, and by improving the food-capture area of the shearing blade during occlusion. The accessory troughs provide an immediately adjacent fragment-clearance area. The increased sophistication of this food-processing system might be particularly important in species that must quickly acquire, chew, and swallow their food and resume echolocating in flight. The common ancestor of bats probably did not have CN in its molars, and the presence of CN does not signal carnivory in bats.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
'Plastrons and adhesive organs' - the functional morphology of surface structures in the broad mite, Polyphagotarsonemus latus (Banks, 1904)
Plastrony i organy przyczepne - morfologia funkcjonalna struktur powierzchniowych u Polyphagotarsonemus latus (Banks, 1904)
Autorzy:
Baker, R.A.
Tematy:
plastron
adhesive organ
functional morphology
morphology
surface structure
mite
egg
male
Polyphagotarsonemus latus
Pokaż więcej
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Powiązania:
https://bibliotekanauki.pl/articles/841823.pdf  Link otwiera się w nowym oknie
Opis:
Consideration is given to the structure and function of the adhesive organ in the male and of the protuberances on the surface of the egg in the Broad mite, Poly phagotarsonemus latus . Scanning Electron microscopy is used to reveal these structures. The adhesive organ serves as a sucker in order that males can carry pharate females. It is believed that the protuberances are part of a discontinuous plastron for gaseous exchange.
Praca jest poświęcona strukturom i funkcjonowaniu organów przyczepnych u samców Polyphagotarsonemus latus oraz strukturze powierzchni jaj tego roztocza. W badaniach posłużono się mikroskopem skaningowym. Organy przyczepne służą samcom do przy trzymywania samic, a struktura widoczna na powierzchni jaj jest pozostałością plastronu
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phenetic relationships among bats of the family Rhinolophidae
Autorzy:
Bogdanowicz, W.
Powiązania:
Acta Theriologica
Opis:
Phenetic analyses, using the common-part-removed transformation of Wood (1983) were performed on 2.5 - 6.4% of the variance that describes morphometric differences among bats of the family Rhinolophidae. Two ordination methods, one clustering technique, and a minimum-spanning tree were employed to assess patterns of similarity among 62 species. Two major phenetic groups were revealed.
Dostawca treści:
RCIN - Repozytorium Cyfrowe Instytutów Naukowych
Książka

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies