scholarly journals Conch structures, soft-tissue imprints and taphonomy of the Middle Ordovician cephalopod Tragoceras falcatum from Estonia

2019 ◽  
Vol 75 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Alexander Pohle ◽  
Christian Klug ◽  
Ursula Toom ◽  
Björn Kröger

Abstract Tragoceras falcatum (Schlotheim, 1820) is a common, loosely coiled estonioceratid (Tarphycerida, Cephalopoda) occurring in the Kunda Regional Stage (early Darriwilian, Middle Ordovician) of Estonia. Although the species is quite well-known, we document some features for the first time. For example, one specimen from the Harku quarry (Estonia) with a phosphatized replacement shell exhibits growth halts (megastriae) on the body chamber. As they are not preserved in smaller specimens, we suggest that these megastriae formed at the approach of maturity, possibly also reflecting sexual dimorphism and cycles of reproduction (iteroparity?). Additionally, the specimen shows minute soft-tissue imprints (drag bands and pseudosutures). These imprints are comparable to patterns in other cephalopods such as ammonoids, bactritids and other nautiloids, but have not yet been reported from Palaeozoic nautiloids. However, they might have been misinterpreted as oncomyarian muscle attachment scars previously. Lastly, we discuss the taphonomy of the specimen, which was encrusted by multiple bryozoan colonies post-mortem. Furthermore, it shows questionable traces of bioerosion.

1976 ◽  
Vol 193 (1113) ◽  
pp. 441-453 ◽  

The ultrastructure and colour of the wing scales of Papilio zalmoxis were studied by means of scanning electron microscopy and spectrophotometry. The colour of the blue scales was found to be mainly of structural origin, due in part to Tyndall scattering by a layer of air-filled alveoli and in part to thin film interference in a basement lamella. A white, fluorescent pigment, probably composed mainly of kynurenine, lines the alveoli, and contributes to the colour principally by virtue of its absorption of ultraviolet radiation. Males and females possess these blue scales, but the overall colour they produce in the wing depends on the distribution of underlying black scales, and this differs between the sexes. The female of this species is figured in colour for the first time. The apparent polymorphism of preserved males was examined and it is concluded, with some reservations regarding the brown form, to be due to post-mortem colour changes. The nature of the coloration and the sexual dimorphism of P. antimachus are described. The sexual dimorphism of both species is discussed.


Geology ◽  
2021 ◽  
Author(s):  
Lesley Cherns ◽  
Alan R.T. Spencer ◽  
Imran A. Rahman ◽  
Russell J. Garwood ◽  
Christopher Reedman ◽  
...  

The extreme rarity of soft-tissue preservation in ammonoids has meant there are open questions regarding fundamental aspects of their biology. We report an exceptionally preserved Middle Jurassic ammonite with unrivaled information on soft-body organization interpreted through correlative neutron and X-ray tomography. Three-dimensional imaging of muscles and organs of the body mass for the first time in this iconic fossil group provides key insights into functional morphology. We show that paired dorsal muscles withdrew the body into the shell, rather than acting with the funnel controlling propulsion as in Nautilus. This suggests a mobile, retractable body as a defense strategy and necessitates a distinct swimming mechanism of hyponome propulsion, a trait that we infer evolved early in the ammonoid-coleoid lineage.


2021 ◽  
Vol 140 (1) ◽  
Author(s):  
Christian Klug ◽  
Alexander Pohle ◽  
Rosemarie Roth ◽  
René Hoffmann ◽  
Ryoji Wani ◽  
...  

AbstractNautilid, coleoid and ammonite cephalopods preserving jaws and soft tissue remains are moderately common in the extremely fossiliferous Konservat-Lagerstätte of the Hadjoula, Haqel and Sahel Aalma region, Lebanon. We assume that hundreds of cephalopod fossils from this region with soft-tissues lie in collections worldwide. Here, we describe two specimens of Syrionautilus libanoticus (Cymatoceratidae, Nautilida, Cephalopoda) from the Cenomanian of Hadjoula. Both specimens preserve soft parts, but only one shows an imprint of the conch. The specimen without conch displays a lot of anatomical detail. We homologise the fossilised structures as remains of the digestive tract, the central nervous system, the eyes, and the mantle. Small phosphatic structures in the middle of the body chamber of the specimen with conch are tentatively interpreted as renal concrements (uroliths). The absence of any trace of arms and the hood of the specimen lacking its conch is tentatively interpreted as an indication that this is another leftover fall (pabulite), where a predator lost parts of its prey. Other interpretations such as incomplete scavenging are also conceivable.


1986 ◽  
Vol 60 (2) ◽  
pp. 400-404 ◽  
Author(s):  
Royal H. Mapes ◽  
N. Gary Lane ◽  
Harrell L. Strimple

An unusual occurrence of a colony of microcrinoids from shale within a fragment of a large orthoconic nautiloid body chamber is described from the Imo Formation (Mississippian, Chesterian) near Elba, Arkansas. The colony, about 70 individuals, consists principally of immature specimens that lack facets for the arms, and a few mature specimens with four or five arm facets. The crinoids are interpreted as record of a census population that was engulfed suddenly by mud. The crinoids are assigned to Allagecrinus coronarius Gutschick, 1968. The body chamber may have been broken during predation by other large cephalopods, or sharks, known from the Imo, or by post-mortem transport. The shell served as a firm substrate on which the microcrinoid larvae could settle and the convex sides may have provided some protection from currents.


Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 226
Author(s):  
Silvio De Luca ◽  
Emanuela Zanardi ◽  
Giovanni Loris Alborali ◽  
Adriana Ianieri ◽  
Sergio Ghidini

The assessment of swine welfare requires feasible, reliable, and reasonable indicators. On-farm evaluation of pig welfare can provide valuable information to veterinarians and farmers. However, such protocols can result expensive and time-consuming. With this regard, an interest in the appraisal of swine welfare at abattoir has grown over the recent years. In particular, the use of certain lesions collected directly from slaughtered animals to determine the welfare status of pigs has been evaluated by several authors. In the present review, the different methods developed to score lesions collected directly from the body and the viscera of animals slaughtered in European abattoirs (“abattoir-based measures”) are presented. The text specifically focuses on the methods currently available in the literature for the scoring of body, pluck and gastric lesions during post-mortem activities. Moreover, the strengths and weaknesses of abattoir-based measures schemes are discussed. To conclude, the future perspectives of the assessment of pig welfare at the slaughterhouse are described, appealing for a benchmarking system that can be systematically used by veterinarians and other professional figures involved in the process.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shreeya Sriram ◽  
Shitij Avlani ◽  
Matthew P. Ward ◽  
Shreyas Sen

AbstractContinuous multi-channel monitoring of biopotential signals is vital in understanding the body as a whole, facilitating accurate models and predictions in neural research. The current state of the art in wireless technologies for untethered biopotential recordings rely on radiative electromagnetic (EM) fields. In such transmissions, only a small fraction of this energy is received since the EM fields are widely radiated resulting in lossy inefficient systems. Using the body as a communication medium (similar to a ’wire’) allows for the containment of the energy within the body, yielding order(s) of magnitude lower energy than radiative EM communication. In this work, we introduce Animal Body Communication (ABC), which utilizes the concept of using the body as a medium into the domain of untethered animal biopotential recording. This work, for the first time, develops the theory and models for animal body communication circuitry and channel loss. Using this theoretical model, a sub-inch$$^3$$ 3 [1″ × 1″ × 0.4″], custom-designed sensor node is built using off the shelf components which is capable of sensing and transmitting biopotential signals, through the body of the rat at significantly lower powers compared to traditional wireless transmissions. In-vivo experimental analysis proves that ABC successfully transmits acquired electrocardiogram (EKG) signals through the body with correlation $$>99\%$$ > 99 % when compared to traditional wireless communication modalities, with a 50$$\times$$ × reduction in power consumption.


Author(s):  
F. Riva ◽  
U. Buck ◽  
K. Buße ◽  
R. Hermsen ◽  
E. J. A. T. Mattijssen ◽  
...  

AbstractThis study explores the magnitude of two sources of error that are introduced when extracorporeal bullet trajectories are based on post-mortem computed tomography (PMCT) and/or surface scanning of a body. The first source of error is caused by an altered gravitational pull on soft tissue, which is introduced when a body is scanned in another position than it had when hit. The second source of error is introduced when scanned images are translated into a virtual representation of the victim’s body. To study the combined magnitude of these errors, virtual shooting trajectories with known vertical angles through five “victims” (live test persons) were simulated. The positions of the simulated wounds on the bodies were marked, with the victims in upright positions. Next, the victims were scanned in supine position, using 3D surface scanning, similar to a body’s position when scanned during a PMCT. Seven experts, used to working with 3D data, were asked to determine the bullet trajectories based on the virtual representations of the bodies. The errors between the known and determined trajectories were analysed and discussed. The results of this study give a feel for the magnitude of the introduced errors and can be used to reconstruct actual shooting incidents using PMCT data.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Raphael Severino Bonadio ◽  
Larissa Barbosa Nunes ◽  
Patricia Natália S. Moretti ◽  
Juliana Forte Mazzeu ◽  
Stefano Cagnin ◽  
...  

AbstractMost biological features that occur on the body after death were already deciphered by traditional medicine. However, the molecular mechanisms triggered in the cellular microenvironment are not fully comprehended yet. Previous studies reported gene expression alterations in the post-mortem condition, but little is known about how the environment could influence RNA degradation and transcriptional regulation. In this work, we analysed the transcriptome of mouse brain after death under three concealment simulations (air exposed, buried, and submerged). Our analyses identified 2,103 genes differentially expressed in all tested groups 48 h after death. Moreover, we identified 111 commonly upregulated and 497 commonly downregulated genes in mice from the concealment simulations. The gene functions shared by the individuals from the tested environments were associated with RNA homeostasis, inflammation, developmental processes, cell communication, cell proliferation, and lipid metabolism. Regarding the altered biological processes, we identified that the macroautophagy process was enriched in the upregulated genes and lipid metabolism was enriched in the downregulated genes. On the other hand, we also described a list of biomarkers associated with the submerged and buried groups, indicating that these environments can influence the post-mortem RNA abundance in its particular way.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Caleb Liang ◽  
Wen-Hsiang Lin ◽  
Tai-Yuan Chang ◽  
Chi-Hong Chen ◽  
Chen-Wei Wu ◽  
...  

AbstractBody ownership concerns what it is like to feel a body part or a full body as mine, and has become a prominent area of study. We propose that there is a closely related type of bodily self-consciousness largely neglected by researchers—experiential ownership. It refers to the sense that I am the one who is having a conscious experience. Are body ownership and experiential ownership actually the same phenomenon or are they genuinely different? In our experiments, the participant watched a rubber hand or someone else’s body from the first-person perspective and was touched either synchronously or asynchronously. The main findings: (1) The sense of body ownership was hindered in the asynchronous conditions of both the body-part and the full-body experiments. However, a strong sense of experiential ownership was observed in those conditions. (2) We found the opposite when the participants’ responses were measured after tactile stimulations had ceased for 5 s. In the synchronous conditions of another set of body-part and full-body experiments, only experiential ownership was blocked but not body ownership. These results demonstrate for the first time the double dissociation between body ownership and experiential ownership. Experiential ownership is indeed a distinct type of bodily self-consciousness.


Author(s):  
Gemma Almond

Abstract This study explores the representation and use of Victorian visual aids, specifically focusing on how the design of spectacle and eyeglass frames shaped ideas of the ‘normal’ and ‘abnormal’ body. It contributes to our understanding of assistive technologies in the Victorian period by showcasing the usefulness of material evidence for exploring how an object was produced and perceived. By placing visual aids in their medical and cultural context for the first time, it will show how the study of spectacle and eyeglass frames develops our understanding of Victorian society more broadly. Contemporaries drew upon industrialization, increasing education, and the proliferation of print to explain a rise in refractive vision ‘errors’. Through exploring the design of three spectacle frames from the London Science Museum’s collections, this study will show how the representations and manufacture of visual aids transformed in response to these wider changes. The material evidence, as well as contemporary newspapers, periodicals, and medical texts, reveal that visual aids evolved from an unusual to a more mainstream device. It argues that visual aids are a unique assistive technology, one that is able to inform our understanding of how Victorians measured the body and constructed ideas of ‘normalcy’ and ‘abnormalcy’.


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