- Taphonomic Processes: Animal Scavenging

2012 ◽  
pp. 350-363
Keyword(s):  
Animal Scavenging ◽  
Taphonomic Processes

The effects of dehydration and local soil on parasite recovery: A preliminary paleoparasitological evaluation on experimental coprolites

The Holocene ◽  
2021 ◽  
pp. 095968362110499
Author(s):  
Darío Alejandro Ramirez ◽  
Mariana Fabra ◽  
Samanta Xavier ◽  
Alena Mayo Iñiguez
Keyword(s):  
Equal Mass ◽  
Central Argentina ◽  
Soil Sediment ◽  
Local Soil ◽  
Before And After ◽  
Fresh Feces ◽  
Flotation Technique ◽  
First Time ◽  
Taphonomic Processes

Experimental paleoparasitological approaches have been used in order to optimize the methodology previously to the application in archeological samples. In this study we evaluated the action of dehydration and local soil (Central Argentina) on the loss of parasite eggs in experimental coprolites, using two parasitological techniques: spontaneous sedimentation and sucrose-flotation. Experimental coprolites comprised fresh human feces, positive for Hymenolepis nana, Ascaris sp., and Enterobius vermicularis, submitted to controlled artificial dehydration. Experimental coprolites with soil addition were prepared by mixing archeological sediment with equal mass of fresh feces. Helminth eggs were counted and eggs per gram were estimated in each subsample. Statistical analyses were applied to compare subsamples before and after desiccation and with and without addition of soil sediment. The performance of parasitological methods statistically differed, the sucrose flotation technique being the less effective when fresh feces and experimental coprolites were analyzed. Partial deformation of eggs was observed via both techniques only in subsamples containing H. nana eggs. However, this was not seen in Ascaris sp. subsamples, possibly due to eggshell composition. We found that sample desiccation significantly decreased the number of eggs in the experimental coprolites. Mixing archeological sediment with the fecal material also resulted in significantly fewer eggs surviving, independent of desiccation. This shows that climate and soil in which archeological fecal samples are found can strongly influence the survival of parasite eggs from past populations. The small amount of parasite evidence often found in paleoparasitological analyses, including Central Argentina, could be attributed to the action of taphonomic processes rather than to the real absence of infection in these ancient populations. Importantly, the study highlights the role of local soil, confirmed for the first time by empirical data. The research provides valuable insights into the understanding of the paleoparasitological results of the region and of general paleoparasitology.

Modernisation of the Hymenoptera: ants, bees, wasps, and sawflies of the early Eocene Okanagan Highlands of western North America

2018 ◽  
Vol 150 (2) ◽  
pp. 205-257 ◽  
Author(s):  
S. B. Archibald ◽  
Alexandr P. Rasnitsyn ◽  
Denis J. Brothers ◽  
Rolf W. Mathewes
Keyword(s):  
North America ◽  
Terrestrial Ecosystems ◽  
Sensu Stricto ◽  
Late Eocene ◽  
Trophic Guilds ◽  
Early Eocene ◽  
Western North America ◽  
Family Level ◽  
Okanagan Highlands ◽  
Taphonomic Processes

AbstractMost major modern families of Hymenoptera were established in the Mesozoic, but the diversifications within ecologically key trophic guilds and lineages that significantly influence the character of modern terrestrial ecosystems – bees (Apiformes), ants (Formicidae), social Vespidae, parasitoids (Ichneumonidae), and phytophagous Tenthredinoidea – were previously known to occur mostly in the middle to late Eocene. We find these changes earlier, seen here in the early Eocene Okanagan Highlands fossil deposits of western North America. Some of these may have occurred even earlier, but have been obscured by taphonomic processes. We provide an overview of the Okanagan Highlands Hymenoptera to family level and in some cases below that, with a minimum of 25 named families and at least 30 when those tentatively assigned or distinct at family level, but not named are included. Some are poorly known as fossils (Trigonalidae, Siricidae, Peradeniidae, Monomachidae), and some represent the oldest confirmed occurrences (Trigonalidae, Pompilidae, Sphecidaesensu stricto, Peradeniidae, Monomachidae, and possibly Halictidae). Some taxa previously thought to be relictual or extinct by the end of the Cretaceous (Angarosphecidae, Archaeoscoliinae, some Diapriidae) are present and sometimes abundant in the early Eocene. Living relatives of some taxa are now present in different climate regimes or on different continents.

Architectural Phases, Use-life Episodes and Taphonomic Processes in Tell Formation:

2020 ◽  
pp. 11-24
Author(s):  
Miquel Molist ◽  
Quim Sisa ◽  
Julia Wattez ◽  
Anna Gómez-Bach
Keyword(s):  
Taphonomic Processes

Subaerial Weathering and Other Terrestrial Surface Taphonomic Processes

2021 ◽  
pp. 403-442
Author(s):  
James T. Pokines ◽  
Christine Spiegel
Keyword(s):  
Taphonomic Processes

Archaeozoology: Methods

2018 ◽  
Author(s):  
Veerle Linseele
Keyword(s):  
Human Life ◽  
Rapid Development ◽  
Mesh Size ◽  
Archaeological Sites ◽  
Complete Understanding ◽  
The Past ◽  
Animal Remains ◽  
Efficient Communication ◽  
Additional Loss ◽  
Taphonomic Processes

Archaeozoology is the study of animal remains, mainly bones and other hard parts, from archaeological sites. It contributes to a more complete understanding of various aspects of human life in the past. Ideally, archaeozoologists, like other specialists, should be involved in the entire process of an archaeological research project, from its design, to fieldwork and data collecting, to final reporting and publication. For efficient communication and fruitful collaboration, the archaeologists involved in this process need to understand the basics of archaeozoological methodology and the range of questions that the discipline can answer. Methods vary among archaeozoologists—not least with regard to quantification—and it is important to be aware of these differences and their possible impact on results when comparing data for different sites. While the actual analysis of animal remains is done by the archaeozoologists, preferably in circumstances where they have access to a comparative collection of recent animal skeletons, the excavation and collection of remains is often the responsibility of the archaeologists. Animal remains are affected by a host of taphonomic processes of loss that are beyond our control. To avoid additional loss of information at the fieldwork stage, appropriate methods are particularly important. The use of sieves with a mesh size no greater than 2 mm is essential in order not to miss the smaller, but no less informative, animal remains. Project leaders play an important role in providing good storage facilities for archaeozoological remains after excavation and after study. With the rapid development in analytical methods, it can be extremely interesting to return to previously studied remains and sample them.

Exceptional Fossil Conservation through Phosphatization

2014 ◽  
Vol 20 ◽  
pp. 59-82 ◽  
Author(s):  
James D. Schiffbauer ◽  
Adam F. Wallace ◽  
Jesse Broce ◽  
Shuhai Xiao
Keyword(s):  
Calcium Phosphate ◽  
Soft Tissues ◽  
Geochemical Processes ◽  
Comprehensive Description ◽  
Animal Evolution ◽  
Pore Fluid Chemistry ◽  
Type Preservation ◽  
Fossil Preservation ◽  
Calcium Phosphate Precipitation ◽  
Taphonomic Processes

This paper addresses the taphonomic processes responsible for fossil preservation in calcium phosphate, or phosphatization. Aside from silicification and rarer examples of carbonaceous compression, phosphatization is the only taphonomic mode claimed to preserve putative subcellular structures. Because this fossilization window can record such valuable information, a comprehensive understanding of its patterns of occurrence and the geochemical processes involved in the replication of soft tissues are critical endeavors. Fossil phosphatization was most abundant during the latest Neoproterozoic through the early Paleozoic, coinciding with the decline of non-pelletal phosphorite deposits. Its temporal abundance during this timeframe makes it a particularly valuable window for the study of early animal evolution. Several occurrences of phosphatization from the Ediacaran through the Permian Period, including Doushantuo-type preservation of embryo-like fossils and acritarchs, phosphatized gut tracts within Burgess Shale-type carbonaceous compressions, Orsten-type preservation of meiofaunas, and other cases from the later Paleozoic are reviewed. In addition, a comprehensive description of the geochemical controls of calcium phosphate precipitation from seawater is provided, with a focus on the rates of phosphate nucleation and growth, favorable nucleation substrates, and properties of substrate tissue and pore-fluid chemistry. It is hoped that the paleontological and geochemical summaries provided here offer a practical and valuable guide to the Neoproterozoic–Paleozoic phosphatization window.

Sign in / Sign up

Export Citation Format

Share Document