Human Ichnology

This study aimed to evaluate the influence of different drying air velocities, with manual and automatic control, on the essential oil and citral content extracted from lemon grass leaves. The drying tests were carried out using a fixed-bed dryer. The treatments were arranged in completely randomized design with a factorial 3x2: three drying air velocity (0.8 m s-1 , 1.3 m s-1 and 1.8 m s-1) and two control system of air velocity (automatic and manual), with three repetitions. The essential oil contents, after drying, were compared with the values obtained from the fresh plant (control). The essential oil extraction was performed by hydrodistillation. The identification and quantification of citral was made by gas chromatography. From the results obtained, it could be concluded that the drying air velocities of 0.8 m s-1 and 1.3 m s-1 with manual control provided the best results for the extraction of essential oil in lemon grass leaves. The different drying air velocities and control system (manual and automatic) did not influence the chemical composition of the essential oils.

We report a Holocene human and animal footprint site from the Namib Sand Sea, south of Walvis Bay, Namibia. Using these data, we explore intratrail footprint variability associated with small variations in substrate properties using a "whole foot" analytical technique developed for the studies in human ichnology. We demonstrate high levels of intratrail variability as a result of variations in grain size, depositional moisture content, and the degree of sediment disturbance, all of which determine the bearing capacity of the substrate. The two principal trails were examined, which had consistent stride and step lengths, and as such variations in print typology were primarily controlled by substrate rather than locomotor mechanics. Footprint typology varies with bearing capacity such that firm substrates show limited impressions associated with areas of peak plantar pressure, whereas softer substrates are associated with deep prints with narrow heels and reduced medial longitudinal arches. Substrates of medium bearing capacity give displacement rims and proximal movement of sediment, which obscures the true form of the medial longitudinal arch. A simple conceptual model is offered which summarizes these conclusions and is presented as a basis for further investigation into the control of substrate on footprint typology. The method, model, and results presented here are essential in the interpretation of any sites of greater paleoanthropological significance, such as recently reported from Ileret (1.5 Ma, Kenya; Bennett et al.

The ichnological record of human traces from Italy is rich and quite diversified. In recent years, the development and dissemination of various methodologies and technological facilities has implemented the re-analysis of this record, enabling to reach different, sometimes deeper, interpretations favoured by the integration of external data, both geological and palaeontological. The oldest occurrence of the human ichnological record from Italy is represented by the Middle Pleistocene ‘Devil’s Trails’ ichnosite in the “Foresta” area (Roccamonfina volcano, southern Italy), depicting human trackmakers trampling a pyroclastic flow deposit while descending a slope about 349 ka. Most of the record is Holocene in age and is constituted by the Upper Palaeolithic Grotta della Basura site (Toirano, northern Italy, about 14 ky), the protohistoric sites of Afragola, Nola and Palma, the area of Pompei and the site of Aosta. The record is enriched by the ichnological evidences preserved in milita...