scholarly journals Experimental Decay of Soft Tissues

2014 ◽  
Vol 20 ◽  
pp. 259-274 ◽  
Author(s):  
Robert S. Sansom
Keyword(s):  
Soft Tissue ◽  
Fossil Record ◽  
Soft Tissues ◽  
Tissue Preservation ◽  
Morphological Transformation ◽  
Decay Data ◽  
Soft Tissue Preservation ◽  
Design Variables ◽  
Wide Range ◽  
Experimental Decay

The exceptionally preserved fossil record of soft tissues sheds light on a wide range of evolutionary episodes from across geological history. Understanding how soft tissues become hard fossils is not a trivial process. A powerful tool in this context is experimentally derived decay data. By studying decay in a laboratory setting and on a laboratory timescale, an understanding of the processes and patterns underlying soft-tissue preservation can be achieved. The considerations and problems particular to experimental decay are explored here in terms of experimental aims, design, variables, and utility. Aims in this context can relate to either reconstruction of the processes of soft-tissue preservation, or to elucidation of the patterns of morphological transformation and data loss occurring during decay. Experimental design is discussed in terms of hypotheses and relevant variables: i.e., the subject organism being decayed (phylogeny, ontogeny, and history), the environment of decay (biological, chemical, and physical) and the outputs (how to measure decay). Variables and practical considerations are illustrated with reference to previous experiments. The principles behind application of experimentally derived decay data to the fossil record are illustrated with three case studies: the interpretation of fossil color, feasibility of fossil embryos, and phylogenetic bias in chordate preservation. A rich array of possibilities for further decay experiments exists and it is hoped that the methodologies outlined herein will provide guidance and a conceptual framework for future studies.

scholarly journals Taphonomic characteristics of fossils on the burgessshale-type spectrum

2018 ◽  
Author(s):  
◽  
Jesse S. Broce
Keyword(s):  
Soft Tissue ◽  
Fossil Record ◽  
Soft Tissues ◽  
Tissue Preservation ◽  
Soft Tissue Preservation ◽  
The Past ◽  
Type Spectrum ◽  
Fossil Preservation ◽  
Available Information ◽  
Evolutionary Lineages

"Study of exceptional fossil preservation tends to yield exciting results. Since soft-bodied organisms and the soft tissues of biomineralizing organisms are usually not preserved in the fossil record, instances of soft-tissue preservation are of immense value to paleontology and biology. Anatomical details of soft tissues are invaluable for understanding the phylogenetic relationships between organisms, as well as interpreting their life modes. Soft-bodied organisms are not only valuable phylogenetically, but they also are important members of ecological community structure. Without soft-tissue preservation, the interpretation of past environments, ecologies, and evolutionary lineages becomes extremely limited. That soft-tissue preservation is relatively rare is an unfortunate phenomenon that not only decreases the amount of available information, but also imposes biases on our understanding of the past. Soft-bodied organisms represent the vast majority of diversity, but are the minority of diversity in the fossil record. In fact, only about 30% of modern marine benthic macroorganisms contain hard parts suitable for easy preservation (Johnson, 1964) and in the Phyllopod Bed of the Cambrian Burgess Shale, only about 14% of species or 2% of individuals have hard parts (Morris, 1986), and consequently would not be preserved in most fossiliferous deposits." -- Introduction

scholarly journals Checklist and Scoring System for the Assessment of Soft Tissue Preservation in CT Examinations of Human Mummies: Application to the Tyrolean Iceman

2017 ◽  
Vol 189 (12) ◽  
pp. 1152-1160
Author(s):  
Stephanie Panzer ◽  
Patrizia Pernter ◽  
Dario Piombino-Mascali ◽  
Rimantas Jankauskas ◽  
Stephanie Zesch ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Scoring System ◽  
Soft Tissues ◽  
Whole Body ◽  
Slice Thickness ◽  
Tissue Preservation ◽  
Soft Tissue Preservation ◽  
Whole Body Ct ◽  
Organ Systems ◽  
Tyrolean Iceman

Purpose Soft tissues make a skeleton into a mummy and they allow for a diagnosis beyond osteology. Following the approach of structured reporting in clinical radiology, a recently developed checklist was used to evaluate the soft tissue preservation status of the Tyrolean Iceman using computed tomography (CT). The purpose of this study was to apply the “Checklist and Scoring System for the Assessment of Soft Tissue Preservation in CT Examinations of Human Mummies” to the Tyrolean Iceman, and to compare the Iceman’s soft tissue preservation score to the scores calculated for other mummies. Materials and Methods A whole-body (CT) (SOMATOM Definition Flash, Siemens, Forchheim, Germany) consisting of five scans, performed in January 2013 in the Department of Radiodiagnostics, Central Hospital, Bolzano, was used (slice thickness 0.6 mm; kilovolt ranging from 80 to 140). For standardized evaluation the “CT Checklist and Scoring System for the Assessment of Soft Tissue Preservation in Human Mummies” was used. Results All checkpoints under category “A. Soft Tissues of Head and Musculoskeletal System” and more than half in category “B. Organs and Organ Systems” were observed. The scoring system accounted for a total score of 153 (out of 200). The comparison of the scores between the Iceman and three mummy collections from Vilnius, Lithuania, and Palermo, Sicily, as well as one Egyptian mummy resulted in overall higher soft tissue preservation scores for the Iceman. Conclusion Application of the checklist allowed for standardized assessment and documentation of the Iceman’s soft tissue preservation status. The scoring system allowed for a quantitative comparison between the Iceman and other mummies. The Iceman showed remarkable soft tissue preservation. Key Points  Citation Format

scholarly journals Distinguishing Biology from Geology in Soft-Tissue Preservation

2014 ◽  
Vol 20 ◽  
pp. 275-288 ◽  
Author(s):  
John A. Cunningham ◽  
Philip C. J. Donoghue ◽  
Stefan Bengtson
Keyword(s):  
Soft Tissue ◽  
Laser Beam ◽  
Evolutionary History ◽  
Soft Tissues ◽  
Analytical Techniques ◽  
Tissue Preservation ◽  
Deep Time ◽  
X Ray ◽  
Soft Tissue Preservation

Knowledge of evolutionary history is based extensively on relatively rare fossils that preserve soft tissues. These fossils record a much greater proportion of anatomy than would be known solely from mineralized remains and provide key data for testing evolutionary hypotheses in deep time. Ironically, however, exceptionally preserved fossils are often among the most contentious because they are difficult to interpret. This is because their morphology has invariably been affected by the processes of decay and diagenesis, meaning that it is often difficult to distinguish preserved biology from artifacts introduced by these processes. Here we describe how a range of analytical techniques can be used to tease apart mineralization that preserves biological structures from unrelated geological mineralization phases. This approach involves using a series of X-ray, ion, electron and laser beam techniques to characterize the texture and chemistry of the different phases so that they can be differentiated in material that is difficult to interpret. This approach is demonstrated using a case study of its application to the study of fossils from the Ediacaran Doushantuo Biota.

scholarly journals Evidence for mummification in Bronze Age Britain

Antiquity ◽  
2005 ◽  
Vol 79 (305) ◽  
pp. 529-546 ◽  
Author(s):  
Mike Parker Pearson ◽  
Andrew Chamberlain ◽  
Oliver Craig ◽  
Peter Marshall ◽  
Jacqui Mulville ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Bronze Age ◽  
Soft Tissues ◽  
Narrow Range ◽  
Tissue Preservation ◽  
Body Parts ◽  
Post Mortem ◽  
Old World ◽  
Soft Tissue Preservation ◽  
The Bronze Age

Ancient Egyptians are thought to have been the only people in the Old World who were practising mummification in the Bronze Age (c. 2200-700 BC). But now a remarkable series of finds from a remote Scottish island indicates that Ancient Britons were performing similar, if less elaborate, practices of bodily preservation. Evidence of mummification is usually limited to a narrow range of arid or frozen environments which are conducive to soft tissue preservation. Mike Parker Pearson and his team show that a combination of microstructural, contextual and AMS 14C analysis of bone allows the identification of mummification in more temperate and wetter climates where soft tissues and fabrics do not normally survive. Skeletons from Cladh Hallan on South Uist, Western Isles, Scotland were buried several hundred years after death, and the skeletons provide evidence of post mortem manipulation of body parts. Perhaps these practices were widespread in mainland Britain during the Bronze Age.

scholarly journals Archaeorhynchuspreserving significant soft tissue including probable fossilized lungs

2018 ◽  
Vol 115 (45) ◽  
pp. 11555-11560 ◽  
Author(s):  
Xiaoli Wang ◽  
Jingmai K. O’Connor ◽  
John N. Maina ◽  
Yanhong Pan ◽  
Min Wang ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Respiratory System ◽  
Lower Cretaceous ◽  
Fossil Record ◽  
Digestive System ◽  
Tissue Preservation ◽  
Air Breathing ◽  
Avian Evolution ◽  
Soft Tissue Preservation ◽  
Tissue Systems

We describe a specimen of the basal ornithuromorphArchaeorhynchus spathulafrom the Lower Cretaceous Jiufotang Formation with extensive soft tissue preservation. Although it is the fifth specimen to be described, unlike the others it preserves significant traces of the plumage, revealing a pintail morphology previously unrecognized among Mesozoic birds, but common in extant neornithines. In addition, this specimen preserves the probable remnants of the paired lungs, an identification supported by topographical and macro- and microscopic anatomical observations. The preserved morphology reveals a lung very similar to that of living birds. It indicates that pulmonary specializations such as exceedingly subdivided parenchyma that allow birds to achieve the oxygen acquisition capacity necessary to support powered flight were present in ornithuromorph birds 120 Mya. Among extant air breathing vertebrates, birds have structurally the most complex and functionally the most efficient respiratory system, which facilitates their highly energetically demanding form of locomotion, even in extremely oxygen-poor environments.Archaeorhynchusis commonly resolved as the most basal known ornithuromorph bird, capturing a stage of avian evolution in which skeletal indicators of respiration remain primitive yet the lung microstructure appears modern. This adds to growing evidence that many physiological modifications of soft tissue systems (e.g., digestive system and respiratory system) that characterize living birds and are key to their current success may have preceded the evolution of obvious skeletal adaptations traditionally tracked through the fossil record.

SEDIMENT COMPOSITION OF BURGESS SHALE TYPE LAGERSTÄTTEN: IMPLICATIONS FOR SOFT-TISSUE PRESERVATION

2016 ◽  
Author(s):  
Ross P. Anderson ◽  
◽  
Nicholas J. Tosca ◽  
Robert R. Gaines ◽  
Derek E.G. Briggs
Keyword(s):  
Soft Tissue ◽  
Tissue Preservation ◽  
Burgess Shale ◽  
Sediment Composition ◽  
Soft Tissue Preservation

scholarly journals Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Toni Wendler ◽  
Torsten Prietzel ◽  
Robert Möbius ◽  
Jean-Pierre Fischer ◽  
Andreas Roth ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Work Experience ◽  
Soft Tissues ◽  
Force Sensor ◽  
Biomechanical Study ◽  
Measuring System ◽  
Wide Range ◽  
Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

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