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The earliest fossil communities of macroscopic organisms are preserved in the Ediacara Biota. While many are difficult to classify into well-known phylogenetic groups, the exceptional preservation of these mostly soft-bodied forms, provides a plethora of material for comprehensive investigations of their biology and ecology. Exceptional deposits of the Ediacara Member from the Flinders Ranges and surrounding areas of South Australia yield abundant Ediacara Biota fossils ideal for such studies. The research presented below targets modular Ediacaran taxa, in particular the iconic and abundant fossil Dickinsonia. Patterns of growth and development in Dickinsonia are explained most parsimoniously via posterior addition of modular units and variable growth rates of units through development regulated to maintain an ovoid shape. Fossiliferous Ediacaran bedding plane surfaces, including the recently uncovered Alice’s Restaurant bed, highlight the heterogeneous distribution of taxa on the Ediacaran seafloor. Trace fossil evidence demonstrates that Dickinsonia and Yorgia were mobile, muscular organisms that fed on the organic mat through their ventral surface. Comparisons with other bilaterally symmetrical modular taxa suggests that many Ediacaran forms may have been mobile but did not engage in activities conducive to trace fossil preservation. Dickinsonia was bilaterally symmetrical, marked by distinct anterior/posterior and likely dorsal/ventral differentiation in addition to modules that met precisely at the midline. Taphonomic variants of Dickinsonia reveal that it was structurally resilient for a soft-bodied organism, highly extensible compared with most modern biopolymers, capable of elastic and plastic deformation, and composed of relatively thick, differentiated tissue. While many of these characters are consistent with bilaterians today this fossil probably represents an extinct clade within the Eumetazoa. This work establishes that the physiology and morphology of Dickinsonia were specifically suited to Ediacaran environments, and that departures from those unique conditions may have led to the ultimate disappearance of this taxa.

Dickinsonia, an iconic member of the Ediacara biota, is abundant in the Ediacaran deposits found at the Nilpena field site, South Australia. Despite exquisite preservation at this site, many specimens of Dickinsonia appear to be incomplete. Orientation measurements from specimens on fossil beds suggest that “missing pieces” are aligned irrespective of the axial orientation of Dickinsonia. The nonrandom orientation of incomplete specimens matches that of aligned structures found on two beds. The directionality of this feature suggests the molding of incomplete specimens under the influence of current activity prior to or during burial. This feature originates where part of a Dickinsonia was lifted off of the substrate during a storm event and sand was deposited beneath this lifted portion. This suggests that Dickinsonia was easily separated from the sea floor and was not attached to the substrate. This is consistent with the data suggesting that Dickinsonia was mobile. Examination of Dickinsonia costata demonstrates ranges in length from 3.6 mm to 167.4 mm and occurs in varying abundance within and across facies. Density data show that this organism preferred a relatively shallow water, fair-weather wave base habitat. The substrate dominated by fossils of Aspidella and Funisia limited the presence of D. costata. Ubiquitous Funisia in the absence of Aspidella preserves larger populations of D. costata, while juvenile forms occur preferentially in an inferred algal-dominated seafloor. The timing of depositional events controlled the maximum size ranges of D. costata, with small populations representing communities buried before they fully developed. The biology of D. costata is reflected in the overall right-skewed, log-normal size frequency curve, demonstrating a pattern of high infant mortality. A single bed contains more than half of the D. costata at Nilpena and the absence of cohorts within this large population is suggestive of continuous recruitment.

This thesis investigates the temperature recorded during the induction sealing process within the headspace of a container. The topic for this thesis stemmed from a question of whether or not the product inside an induction sealed bottle has the potential of being adversely affected by heat generated during the induction sealing process on a packaging line during production. The thesis demonstrated the heat generated and temperature recorded utilizing irreversible chemical temperature indicating labels during the induction sealing process on a standard bottle packaging line with an aluminum foil liner/innerseal. Based on the results of this study, the following trends were observed: as the induction seal head height increased above the container/closure system, the temperature at the foil innerseal decreased and the distance from the top of the bottle finish down into the bottle headspace that a temperature could be measured decreased. As the packaging line speed increased, the temperature at the foil innerseal decreased and the distance measured from the top of the bottle finish down into the bottle headspace that a temperature could be measured decreased. As the diameter of the foil innerseal increased with the increase in closure diameter, the temperature at the foil innerseal increased and the distance measured from the top of the bottle finish down into the headspace that a temperature could be measured increased. In no case did the temperature at the product fill level of any of the tested container/closure systems exceed 100F. Therefore it can be concluded that the induction sealing process does not introduce temperatures high enough that would adversely affect the contents of a container/closure system.