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Forensic science uses multiple methods to assess the circumstances surrounding the death of an individual including the presence and abundance of taphonomic species. Postmortem intervals (PMI) define the time that has passed from the death of an individual to their discovery. Observing insect and bacterial species found on corpses aids in the determination of the duration of the PMI as specific decay stages are predominated by distinct species. These ranges of predominance can be altered due to variability in the surrounding environment, such as temperature fluctuations associated with climate change. Our understanding of how temperature increases affect the abundance and temporal appearance of specific bacterial species is unknown. Fluctuations, such as the increase in temperature, are speculated to result in the increased rate of decay while decreasing bacterial species sensitive to elevated temperatures. We tested the rate of decay with respect to bacterial species in a laboratory setting. Rats were buried into 4 inches of soil and exposed to elevated temperature ranges of 6.0 °C and 3.0 °C higher than ambient temperature with ambient temperature as the control group. Bacterial samples are collected before skeletonization occurs and assessed by qPCR using the 2-ΔΔCT method to determine the differences in the abundance of bacteria between treatment groups. Visual assessment of the decomposition was recorded each day by photographs. We expect these findings to provide information on climate change effects on postmortem forensic analysis in regards to bacterial species known for decomposition. [ABSTRACT FROM AUTHOR]

Exceptionally preserved fossils can inform our interpretations of life on early Earth and potentially habitable extraterrestrial environments. Silica deposits in carbonate strata of Proterozoic Era tidal environments commonly preserve such exceptional microbial fossils. The process of silicification is not well understood in these environments and changes in the Earth's silica cycle mean that there are no modern analogs for these environments. In such cases, actualistic experiments can provide insight into the fossilization process in these deposits. With their expansion on the definition of taphonomy, Anna Behrensmeyer and Susan Kidwell emphasized that information can be gained from taphonomy and used to infer conditions in paleoenvironments and ecosystems. Results of actualistic taphonomic experiments designed using extant microorganisms as analogs for those seen in silica deposits are presented here. These experiments build on those performed by Julie Bartley (1996) and identify diagenetic pathways for microorganisms analogous to those preserved in Proterozoic strata. Previous experiments have documented morphological changes resulting from biological decomposition of filamentous and coccoidal microbes; however, these experiments used monocultures. The research presented here uses microbial consortia to explore patterns of biological decomposition and its effects on mat textures and individual morphologies. Decomposition pathways for each microbial mixture closely resemble the modeled and observed pathways for monocultures in Manning-Berg, Selly, and Bartley (2021). [ABSTRACT FROM AUTHOR]

Here we describe an individual gomphothere specimen recovered from Esmeralda County, Nevada. It was recovered from an area known as "The Sump," just 18 miles north of Dyer, NV, currently dominated by badland topography. Remnants of a paleo-forest are visible in the highlands of the site, while the central basin exposes mudrocks and sandstones, interfingered in places by several chalky, volcaniclastic layers. The sediments denote a past marsh environment, an ideal feeding ground for browsers of C3 plant material, such as trees and shrubs. A slot canyon feeds the inactive channel where the discovery was made. Sedimentary units of the Esmeralda Formation in the vicinity of the north end of Fish Lake Valley have previously been interpreted as Miocene (Claredonian North American Land Mammal Age). The Gomphotheriidae were a family of proboscideans, widespread throughout the late Cenozoic era. Gomphotheres radiated throughout North America during the Miocene epoch, and diversified throughout the continent until their extinction in the late Pleistocene. Several species were participants in the Great American Biotic Interchange, but only three have been recorded from South America. Gomphotheres likely filled the niche of a dominant megafaunal browser, as their dentition and body morphology suggest that they were opportunistic feeders with a preference for C3 browse. The recovered specimen represents the maxillae, portions of the premaxillae, as well as the palatine, all in articulation. After removal of sediment with an air scribe, anterior and posterior sinus cavities were revealed. Two molars are present, and a portion of both tusks have been preserved within their cranial sockets. We attribute this specimen to Gomphotherium minor based upon the combination of small potential skull size with the extremely worn occlusal surface of the preserved molars of the individual. Modern elephants exhibit similar tooth wear towards the end of their lives, eventually succumbing to starvation. Mawby (1968) described Megabelodon minor (later synonymized with Gomphotherium by Tobien 1973) based on a tuskless mandible recovered from the same formation. Diagnostic measurements of the teeth, maxillae, and palate were taken and compared to the type specimen and other longirostrine proboscideans. We believe that the individual collected from the Sump is of the same species, but this is difficult to confirm due to our lack of a dentary present. [ABSTRACT FROM AUTHOR]

The early Oligocene Forest Hill Formation (Vicksburg Group) in Mississippi is a nearshore terrestrial unit consisting of laminated sands, and dark carbonaceous clays with lignite beds. In 2020, two palynological samples were collected by coauthors: one from Smith County and the other from Yazoo County, near Satartia. Both samples contain an abundance of well-preserved and diverse palynomorphs of pollen, spores, and algal cysts indicative of a warm temperate environment. The Smith County sample is associated with a rich and diverse assemblage of well-preserved plant macrofossils, including palm fronds along the fissile bedding planes of fresh exposures. Palynomorphs from this site are representative of an oak-hickory-willow coastal forest bordering freshwater riverbanks and a storm surge zone flanking the eastern side of the Mississippi Embayment. In a 300-point count, angiosperms comprised 59%, conifers 11.4%, pteridophyte trilete spores 19%, monolete spores 1.5%, freshwater algal forms 9% and dinoflagellates cysts and acritarchs 1.5% of the assemblage. The Yazoo County sample was collected at the most northern and up-dip limit exposure of the formation along the axis of the Mississippi Embayment. This sample indicated a backwater, enclosed bay setting based on the higher quantity of Anemia (22%) and Cyathidites (7%) spores. In this 300-point count, angiosperms comprised 48%, conifers 3%, spores 40%, and freshwater algal forms 9% of the assemblage. Common pollen types include Aquifoliaceae, Arecaceae, Betulaceae, Chenopodiaceae, Cornaceae, Fabaceae, Fagaceae, Juglandaceae, Malvaceae, Oleaceae, Platanaceae, Salicaceae, Ulmaceae, and the form genera Liliacidites and Tetracolporites. Conifers include Cupressaceae and Pinaceae. Spores include Anemia, Dictyophyllidites, Lycopodioideae, Ophioglossaceae, Osmundaceae, Polypodiaceae, Sphagnum, among others. A few unidentified dinoflagellates and freshwater algal cysts of Zygnemataceae were also noted. The pristine preservation of the palynomorphs suggests that they are primarily of local origin. [ABSTRACT FROM AUTHOR]