Search results for "Appendage"
showing 10 items of 33 documents
The morphology, ontogeny, and inferred behaviour of the deep-sea echinoid Calymne relicta (Holasteroida).
2009
The deep-sea holasteroid Calymne relicta was first described from a few fragments discovered by the HMS ‘Challenger’ in the Bermuda abyssal plain more than a century ago. In addition to re-examining the type material, we describe herein new specimens from unpublished material collected between 3720 and 4860 m during three scientific expeditions that took place on both sides of the North Atlantic between 1966 and 1991. The new material includes juvenile and adult specimens in sufficiently good preservational state to allow a full redescription, including all types of appendages, some of which have never been described. These new observations confirm the atypical characteristics of C. relicta…
Comment on “An early Late Triassic long-necked reptile with a bony pectoral shield and gracile appendages” by Jerzy Dzik and Tomasz Sulej
2017
Comment on “An early Late Triassic long-necked reptile with a bony pectoral shield and gracile appendages” by Jerzy Dzik and Tomasz Sulej
Exceptionally preserved soft parts in fossils from the Lower Ordovician of Morocco clarify stylophoran affinities within basal deuterostomes.
2019
10 pages; International audience; The extinct echinoderm clade Stylophora consists of some of the strangest known deuterostomes. Stylophorans are known from complete, fully articulated skeletal remains from the middle Cambrian to the Pennsylvanian, but remain difficult to interpret. Their bizarre morphology, with a single appendage extending from a main body, has spawned vigorous debate over the phylogenetic significance of stylophorans, which were long considered modified but bona fide echinoderms with a feeding appendage. More recent interpretation of this appendage as a posterior “tail-like” structure has literally turned the animal back to front, leading to consideration of stylophorans…
Isomeric arrangement of the left atrial appendages and visceral heterotaxy: two atypical cases.
2000
AbstractWe present two cases in which there was isomeric arrangement oi the left atrial appendages in association with multiple spleens and complete heart block. In both of these, the venous connections were normal. In one case the arrangement of the bronchial tree and the lungs was normal, the liver was left-sided, and the stomach was right-sided. In the other case, there was left isomeric broncho-pulmonary morphology, and both liver and stomach were right-sided. These unusual combinations show the need for full description of the morphology of other organs, and the venoatrial connections, in cases with isomeric arrangement of the atrial appendages. They also demonstrate that connection of…
Ontogeny of the Calliandra – massulae (Mimosaceae: Ingeae), and the associated viscin body
2006
Abstract Polyads, called also massulae, are common in the Mimosaceae. Within this family, only in Calliandra (s. l.) polyads show a remarkable morphological variation: 16-grained lens-shaped massulae in the neotropical Zapoteca (syn. Calliandra p.p.), and highly asymmetric eight-grained massulae in Calliandra (s. str.). As a further specialisation the massulae in Calliandra (s. str.) possess a sticky appendage called a viscin body. The form and ontogeny of this unique two-dimensional construction of the massula is of particular interest. In Calliandra (s. str.) the octad is normally the developmental product of the initiation stage, beginning with one pollen mother cell (PMC). In total, Cal…
Case of unilateral wing formation in the female of the glowwormLampyris noctiluca
2003
On July 27, 1999, the first author found a unilaterally winged adult glowworm in a park in the city of Mainz. Except for the wings on the left side, the specimen exhibited female characteristics that extended to external sexual appendages, the lantern and the gonads. The internal organization showed some remarkable differences between right (wingless) and left (winged) side. The right ovary contained three times more mature eggs than the left side and the volume of the corpus allatum of this side was about one-third larger than that of the left side. This suggests that aptery and egg maturation are affected by corpus allatum activity, i.e., juvenile hormone production. The findings do not s…
Ontogeny of Heterocypris bosniaca (Ostracoda: Cyprididae): description of postembryonic instars and rediscovery of the neglected A-9 stage
2013
Despite being the most common and widespread family of Ostracoda in fresh water, the Cyprididae are still poorly known with respect to species ontogeny. The full series of eight juvenile instars has been described in detail for just five of the approximately 1000 living species, and only in one case did this include the earliest A-9 stage. We aimed to fill this gap with a morphological study of the post-embryonic development of Heterocypris bosniaca Petkowski, Scharf and Keyser, 2000, a species with unusual morphological traits within the genus, including putatively paedomorphic characters such as valves without tubercles and the narrow calcified inner lamella on both valves. Inside the egg…
Initial and long-term antithrombotic therapy after left atrial appendage closure with the WATCHMAN
2020
Abstract Background Evidence regarding post-procedural antithrombotic regimes other than used in randomized trials assessing percutaneous left atrial appendage (LAA) closure is limited. Purpose The present work aimed to compare different antithrombotic strategies applied in the real-world EWOLUTION study. Methods A total of 998 patients with successful WATCHMAN implantation at 47 centers were available for the present analysis. The composite ischemic endpoint of stroke, TIA, systemic embolism and device thrombus as well as the bleeding endpoint defined as at least major bleeding according to BARC were assessed during an initial period (from implant until first medication change) and long-te…
Change in take-off elevation angle after limb autotomy mitigates the reduction in jumping distance in rice grasshoppersOxya yezoensis
2013
Autotomy is the ability to spontaneously self-amputate a limb or other appendage, often as a reflexive action. This limb amputation typically occurs as a specialized defensive response to an attack from a predator and thereby enables the prey to escape from predation. Despite the benefits of escape, autotomized organisms lose the body part and its associated function. Here, we investigated the jumping behavior and performance of one-leg-autotomized and intact rice grasshoppers, Oxya yezoensis, to examine changes in jumping behavior after autotomy. The take-off elevation of autotomized grasshoppers was 7.8° lower than in intact grasshoppers, resulting in nearly a 45° angle of take-off, which…
A ciliopathy complex builds distal appendages to initiate ciliogenesis
2021
ABSTRACTCells inherit two centrioles, the older of which is uniquely capable of generating a cilium. Using proteomics and super-resolved imaging, we identified a module which we term DISCO (DIStal centriole COmplex). DISCO components CEP90, MNR and OFD1 underlie human ciliopathies. This complex localized to both distal centrioles and centriolar satellites, proteinaceous granules surrounding centrioles. Cells and mice lacking CEP90 or MNR did not generate cilia, failed to assemble distal appendages, and did not transduce Hedgehog signals. Disrupting the satellite pools did not affect distal appendage assembly, indicating that it is the centriolar populations of MNR and CEP90 that are critica…