Wyniki wyszukiwania - Biblioteka Nauki

1

Oviraptorosaur tail forms and functions

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Persons,IV W. S. , Currie P. J. , Norell M. A.

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tom 59

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nr 3

EN

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.

2

Morphological specializations of Cheiromeles (naked bulldog bats; Molossidae) and their possible role in quadrupedal locomotion

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Schutt,Jr. W. A. , Simmons N. B.

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tom 03

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nr 2

EN

Two molossids, Cheiromeles torquatus and C. parvidens, display a number of morphological characteristics that appear unique among Chiroptera. In this study, adult specimens of both species (fluid-preserved and skeletons) were examined using a dissecting microscope and camera lucida. Several unique morphological features are described in detail for the first time with comments on their possible functions. These include a hallux (digit I) that is positioned at a right angle to digits II-V, a calcar that is bound to m. gastrocnemius, and a modified m. tensor plagiopatagii which appears to function like a drawstring to close a pair of subaxillary 'pouches'. The function of these structures and additional characteristics of the limbs appear related to terrestrial and arboreal locomotion exhibited by these bats.

3

Flowering biology and pollen production of four species of the genus Rosa L.

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Zuraw B. , Sulborska A. , Stawiarz E. , Weryszko-Chmielewska E.

Acta Agrobotanica

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2015

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tom 68

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nr 3

EN

Wild growing rose species are of great importance as a source of pollen for insects. Oil extracted from the petals of various Rosa species is used in perfumery, cosmetic industry, and therapeutics. In our study, we compared the flowering duration and flower lifespan, the number of stamens and pistils, the mass and size of pollen grains as well as the anatomical features of the petals of four Rosa species: R. canina, R. ×damascena, R. gallica, and R. rugosa. Moreover, we examined the pollen loads collected by bumblebees foraging on rose flowers in order to determine the attractiveness of pollen of this genus to insects. We showed the flower lifespan to vary (3.5–8 days) in the roses studied and revealed high variation in the number of stamens (82–260) and pistils (17–65) as well as in the mass of pollen produced. The flowers of R. rugosa produced the highest amount of pollen (26.7 mg per flower), while the flowers of R. canina the least (3.3 mg per flower), which is associated with differences in the number of stamens developed in the flowers between these species. The largest pollen grains were found in R. ×damascena and R. gallica. We demonstrated that R. ×damascena produces the thickest petals and that scent-emitting papillae found on the adaxial surface of the petals differ in size and shape in the rose species investigated.

PL

Dziko rosnące gatunki z rodzaju róża (Rosa) mają duże znaczenie jako źródło pyłku dla owadów. Uzyskiwany z płatków olejek znalazł zastosowanie w perfumerii, przemyśle kosmetycznym i lecznictwie. W pracy porównano długość okresów kwitnienia, długość życia kwiatów, liczbę pręcików i słupków, masę i wielkość ziaren pyłku oraz cechy anatomiczne płatków czterech gatunków z rodzaju Rosa: R. canina, R. ×damascena, R. gallica i R. rugosa. Wykazano różną długość życia kwiatów badanych róż (3.5–8 dni) oraz duże zróżnicowanie w liczbie pręcików (82–260) i słupków (17–65), a także w masie produkowanego pyłku. Najwięcej pyłku wytwarzają kwiaty R. rugosa (26.7 mg/kwiat), najmniej kwiaty R. canina (3.3 mg/kwiat), co jest związane w dużej mierze z różną pomiędzy gatunkami liczbą pręcików w kwiatach. Największe ziarna pyłku stwierdzono u R. ×damascena i R. gallica. Wśród badanych gatunków róż najgrubsze płatki wytwarza R. ×damascena, a występujące na doosiowej powierzchni płatków papille emitujące zapach różnią się wielkością i kształtem. Udział pyłku Rosa w obnóżach pyłkowych zebranych przez trzmiele oblatujące kwiaty róż jest dominujący i wynosi >90%.

4

Phenetic relationships among bats of the family Rhinolophidae

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Bogdanowicz W.

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1992

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tom 37

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nr 3

5

Palaeobiology and evolutionary context of Angulithes mermeti, a streamlined early Late Cretaceous shallow - water nautiloid

80%

Wilmsen M. , Nagm E.

Acta Palaeontologica Polonica

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2019

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tom 64

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nr 4

EN

Cretaceous nautiloids are commonly characterized by inflated shells and prolonged stratigraphic ranges. In the Albian, the species of Angulithes appeared and compressed, short-lived forms with narrow venters emerged during the Cenomanian age. Based on a new description, the late Cenomanian nautiloid Angulithes mermeti is discussed with its palaeobiological background and placed in an evolutionary context of the Cenomanian lineage of Angulithes, considering contemporaneous palaeoenvironmental changes and inferred functional traits. A. mermeti is characterized by a nearly oxycone shell with sharp venter and narrow umbilicus, a fairly sinuous suture, low inter-septal distances, and an almost dorsal siphuncle. Its palaeobiogeographical occurrence was latitudinally restricted to shallow tropical–subtropical shelf seas with a preferred habitat depth between 5–50 m. Several morphological trends reflected by the Cenomanian species of the genus culminated in the late Cenomanian species A. mermeti, i.e., (i) increasing shell compression and sharpening of the venter, (ii) increasing folding of the septa, (iii) reduction of inter-septal distances, and (iv) dorsally directed migration of the siphuncle. The hydrodynamically efficient form was favorable to successfully populate the wide and shallow epicontinental seas that formed during the Cenomanian age. The increasing sutural sinuosity and the dense septal spacing aimed to buttress the shells against shell-breaking predators while the functional reason for the dorsal- directed migration of siphuncle is more elusive; it may have improved the efficiency of the hydrostatic apparatus and its internal position is beneficial in the case of predation, too. The gradual morphological change in the Cenomanian lineage of the genus Angulithes provides a well-constrained case study of rapid evolutionary response to major environmental pressure, i.e., the opening of newly available niches in the course of the great early Late Cretaceous transgression, in an otherwise rather bradytelic biotic group.

6

Functional morphology and biomechanics of the cynodont Trucidocynodon riograndensis from the Triassic of Southern Brazil: Pectoral girdle and forelimb

80%

de Oliveira T. V. , Schultz C. L.

Acta Palaeontologica Polonica

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2016

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tom 61

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nr 2

EN

Non-mammalian cynodonts provide insights on several points about mammalian evolution, such as the postural change and locomotory advances within the group. Unfortunately, complete skeletons of Triassic cynodonts are rather uncommon and where more complete specimens are found they can offer a global vision on some traits not available from partial specimens. This is the case of the cynodont Trucidocynodon riograndensis, from the Triassic of Brazil, that has preserved its forelimbs providing some insights into locomotory properties. The movements between interclavicle and clavicle must have been limited, as such as those occurring between the latter and the scapulocoracoid although the long acromion process of this should have permitted a greater degree of freedom. Some of the more significant movements were those on the shoulder joint, in which the maximum adduction should have been ca. 35º relative to the parasagittal plane and the greater abduction ca. 55º. The maximum adduction occurred when the humerus was in the more retracted position during stride and the variation in the adduction/abduction should have been significant to the limb posture during its recovery stroke. The long olecranon and the distal overlapping between radius and ulna suggest the predominance of simple flexion/extension on the forearm without significant pronation/supination. The poorly preserved hand suggests that Trucidocynodon could have evolved a slight semidigitigrad condition in its forelimbs. All these features give to this cynodont an important role in the evolution of the mammalian locomotory properties indicating that some features, such as the possibility of greater humeral adduction, evolved early in cynodont lineage.

7

Functional morphology and modifications on spine growth in the productid brachiopod Heteralosia slocomi

80%

Perez-Huerta A.

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2013

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tom 58

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nr 2

EN

Spines are one of the most characteristic ornamenting features of many fossil brachiopod taxa. Despite several studies of spines in different species, there is still insufficient information about the development, functionalmorphology, andmodifications of brachiopod spines. In particular, ontogenetic data are very rare and the understanding of the relationship between functional morphology and paleoecology is elusive. The present study analyzes the functional morphology and modifications on spines of the Pennsylvanian brachiopod species Heteralosia slocomi throughout ontogeny. Spines are tubular hollow and only displayed on the surface of the ventral valves, where they develop from a specific point at the margins of the growth lamellae and directed towards the anterolateral margins.Modifications of up to 180 from this original direction of growth are observed in response to ecological pressure and biotic interactions. The function of these spines is primarily for attachment by clasping and cementation, but the possibility of spines acting as sensory mechanisms is not excluded.

8

Evidence for a sauropod-like metacarpal configuration in stegosaurian dinosaur

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Senter P.

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nr 3

427-432

EN

The stegosaurian forelimb is usually portrayed with the metacarpals slanted and distally spread. However, manual manipulation of stegosaurian metacarpals reveals that in that configuration they do not articulate with each other nor with the rest of the forelimb. Rather, they do articulate with each other and with the rest of the forelimb when posed vertically and arranged in a compact, semi−tubular configuration, as in sauropods. This configuration agrees with data from articulated specimens and trackways. As with sauropods, this metacarpal configuration makes retention of phalanges awkward for locomotion and may be functionally related to the vestigiality of the manual phalanges of the outer digits.

9

Ultastructure of the ventral lateral geniculate nucleus [LGNv] receiving tectal afferents in the cat

80%

Noseworthy M. D. , Partlow G. D.

Acta Neurobiologiae Experimentalis

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1992

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tom 52

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nr 2

10

A new Middle Cambrian stem-group echinoderm from Spain: Palaeobiological implications of a highly asymmetric cinctan

80%

Zamora S. , Smith A. B.

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2008

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tom 53

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nr 2

EN

A new exquisitely preserved stem group echinoderm (cinctan), Lignanicystis barriosensis gen. et sp. nov., is described from the Middle Cambrian of Los Barrios de Luna, North Spain. This displays a unique asymmetrical body plan with ventral projecting nodes that raised the lower surface above the substratum. There are four openings through the body wall: mouth, anus, atrium, and an aligned row of sutural pores of uncertain function. Unlike other cinctans, Lignanicystis has a strongly asymmetrical shape convergent with that of some cornute carpoids. Like cornutes, the test is also elevated above the substratum to allow water flow beneath the theca. In both cases this is probably an adaptation to life in higher water flow regimes.

11

New findings reveal that the Middle Triassic ichthyosaur Mixosaurus cornalianus is the oldest amniote with a dorsal fin

70%

Renesto S. , Dal Sasso C. , Fogliazza F. , Ragni C.

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nr 3

12

Two new species of entobdelline skin parasites [Monogenea, Capsalidae] from the blotched fantail ray, Taeniura meyeni, in the Pacific Ocean, with comments on spermatophores and the male copulatory apparatus

70%

Whittington I. D. , Kearn G. C.

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nr 1

12-21

EN

We made a comparative anatomical study of entobdelline monogenean skin parasites from the blotched fantail ray, Taeniura meyeni (= T. melanospila) from public aquaria and fish-holding facilities distributed widely across the western Pacific Ocean. These facilities were located in Australia (Mooloolaba, southern Queensland; Cairns, northern Queensland), Taiwan and Japan. The capture localities of the aquarium fishes are unknown to us, with the exception of the individual fish from northern Queensland which came from Sudbury Reef, a local inshore reef. Entobdellines from southern Queensland differed morphologically from those from northern Queensland and Taiwan and the 2 new monogenean species are described and named Neoentobdella garneri sp. nov. and N. taiwanensis sp. nov., respectively. We determined that an entobdelline collected by Dyer and co-workers from a ray identified as T. melanospila (= T. meyeni) from an aquarium in Okinawa, Japan and identified by them as Entobdella squamula (Heath, 1902) Johnston, 1929 was misidentified and is tentatively assigned to N. taiwanensis sp. nov. The male copulatory organ of each new species resembles a penis, but evidence that these organs are eversible like a cirrus is presented. Caution is advised in deciding whether the male copulatory organs of capsalids may function as a penis or as a cirrus and we suggest that possession of a penis versus a cirrus may not necessarily indicate wide evolutionary divergence. In N. garneri, spermatophores consist of a sausage-shaped capsule and a long hollow stalk. A spermatophore received from a donor is anchored in the vagina by means of the stalk, with the capsule protruding outside the body.

13

A new genus and new species of microbothriid monogenean [Platyhelminthes] with a functionally enigmatic reproductive system, parasitic on the skin and mouth lining of the largetooth sawfish, Pristis microdon, in Australia

61%

Kearn G. C. , Whittington I. D. , Evans-Gowing R.

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nr 2

115-122

EN

Dermopristis paradoxus gen. et sp. nov., a microbothriid monogenean parasite from the skin and mouth lining of the largetooth sawfish, Pristis microdon (Elasmobranchii, Pristidae) in Australia, is described. The parasite has 2 juxtaposed testes and differs from other microbothriids in possessing a unique and unusual terminal male reproductive tract comprising a proximal and a distal tube, the latter with a conspicuous opening on the ventral surface and lacking a recognisable male copulatory organ. The smalltooth sawfish, P. pectinata, also has a skin-parasitic microbothriid, Dermophthirioides pristidis Cheung et Nigrelli, 1983, but this parasite species has a prominent copulatory papilla. Dermopristis paradoxus also has parallel ridges with broad tops running in a roughly transverse direction across the ventral surface of the body. The ventral ridges are prominent from the level of the pharynx to the posterior region of the body. The function of the ridges is unknown. Reproductive biology, attachment and feeding in D. paradoxus are discussed. In the absence of unmounted parasite specimens for sectioning, a mounted specimen of D. paradoxus was released from the slide and successfully processed to provide serial, stained, resin sections. This useful technique is recommended to provide anatomical information in situations where only specimens on slides are available for study.