A review of the dodo and its ecosystem: insights from a vertebrate concentration Lagerstätte in Mauritius

The dodo Raphus cucullatus Linnaeus,1758, an extinct and flightless, giant pigeon endemic to Mauritius, has fascinated people since its discovery, yet has remained surprisingly poorly known. Until the mid-19th century, almost all that was known about the dodo was based on illustrations and written accounts by 17th century mariners, often of questionable accuracy. Furthermore, only a few fragmentary remains of dodos collected prior to the bird's extinction exist. Our understanding of the dodo's anatomy was substantially enhanced by the discovery in 1865 of subfossil bones in a marsh called the Mare aux Songes, situated in southeastern Mauritius. However, no contextual information was recorded during early excavation efforts, and the majority of excavated material comprised larger dodo bones, almost all of which were unassociated. Here we present a modern interdisciplinary analysis of the Mare aux Songes, a 4200-year-old multitaxic vertebrate concentration Lagerstätte. Our analysis of the deposits at this site provides the first detailed overview of the ecosystem inhabited by the dodo. The interplay of climatic and geological conditions led to the exceptional preservation of the animal and associated plant remains at the Mare aux Songes and provides a window into the past ecosystem of Mauritius. This interdisciplinary research approach provides an ecological framework for the dodo, complementing insights on its anatomy derived from the only associated dodo skeletons known, both of which were collected by Etienne Thirioux and are the primary subject of this memoir.Additional co-authors: Anneke H. Van Heteren, Vikash Rupear, Gorah Beebeejaun, Alan Grihault, J. (Hans) Van Der Plicht, Marijke Besselink, Juliën K. Lubeek, Max Jansen, Hege Hollund, Beth Shapiro, Matthew Collins, Mike Buckley, Ranjith M. Jayasena, Nicolas Porch, Rene Floore, Frans Bunnik, Andrew Biedlingmaier, Jennifer Leavitt, Gregory Monfette, Anna Kimelblatt, Adrienne Randall, Pieter Floore & Leon P. A. M. Claessen

The Effects of Holocene Landscape Changes on the Formation of the Archaeological Record in the Fayum Basin, Egypt

Geoarchaeological research was performed across an archaeological landscape along the hyperarid northern paleoshores of the modern Lake Qarun, Fayum Basin, Egypt. Objectives were to record sedimentary variability and to consider the correlation between the paleoenvironmental interpretations of these sedimentary data and the observed archaeological record dated to the early and mid-Holocene. Our approach combines hand-drilling and stratigraphic descriptions with detailed studies of sediments (grain size analysis, analyses of CaCO3, and organic matter contents), densities of stone artifacts and bones, and chronometric data from associated contexts (AMS 14C dates on charcoal from hearths). Analysis of deposits indicates initiation of lake deposition, reworking of lake deposits, and subsequent accumulation of wind-blown deposits occurred prior to the deposition of archaeological materials. Correlations between sediment and the archaeological deposits indicate a different use of areas covered by relatively coarse-grained sediment (sand) compared to areas where relatively fine-grained deposits are exposed (clay and silt). Reassessment of the associations between archaeological materials and sediments in the Fayum Basin is required to improve knowledge of the interrelationships between the Nile flood history, regional climatic changes, oscillations in levels of paleo-Lake Qarun, compared to the chronology of human occupation in the Fayum Basin

The option of Roman canal construction by Drusus in the Vecht river area (the Netherlands): A geoarchaeological approach

This paper presents a geoarcheological study on potential canal subsections present in the Roman-age Vecht branch of the Rhine-Meuse delta (the Netherlands).The first Roman canals in this delta were dug around 12 BC by Drusus, but their location has been the subject of debate since the 16th century, with various hypotheses proposed. Based on actual palaeogeographical knowledge of the Rhine-Meuse delta, the Utrechtse Vecht hypothesis is considered the most plausible. Within the study area, in the northern part of the Vecht system, natural sections of this river may alternate with possible artificial reaches, created at the time of Drusus. Such artificial canals, being part of an otherwise natural channel belt system, can widen and deepen overtime, eroding all or most of the recognizable features associated with their original construction. As study area was chosen a relatively straight section of the Vecht between two former lakes. Two approaches were used. The first approach centred upon mapping channel morphology and recording sediment stratigraphy of the river deposits through detailed auger coring. Results corroborated the hypothesis of an originally straight feature (landform), confirming that it might have started life as a dug course, but not providing preserved archaeological remains of this stage. The second approach was chronological, whereby a programme of 14C dating was undertaken to refine the understanding of the origin and development of this reach of the Vecht, allowing earlier chronological investigations to be further contextualised and reassessed. A significant challenge to understand age control and floodplain evolution is the degradation of the top of the clayey peat that was observed below the levee deposits; this degradation is due to the lowering of groundwater levels and causes the end of peat growth to be dated as older than it actually is. Using new radiocarbon dates we have reconstructed that the Overmeer-Nigtevecht reach of the Vecht between two former lakes started life as a straight channel. We have constrained its age to be closer to the time of Drusus' activities (early Roman age). Although we have not found in situ remains of Drusus canal(s), these two new insights make the Vecht option, effectuated by a series of short canals, more likely to be the Drusus canal(s)

The option of Roman canal construction by Drusus in the Vecht river area (the Netherlands): A geoarchaeological approach

This paper presents a geoarcheological study on potential canal subsections present in the Roman-age Vecht branch of the Rhine-Meuse delta (the Netherlands).The first Roman canals in this delta were dug around 12 BC by Drusus, but their location has been the subject of debate since the 16th century, with various hypotheses proposed. Based on actual palaeogeographical knowledge of the Rhine-Meuse delta, the Utrechtse Vecht hypothesis is considered the most plausible. Within the study area, in the northern part of the Vecht system, natural sections of this river may alternate with possible artificial reaches, created at the time of Drusus. Such artificial canals, being part of an otherwise natural channel belt system, can widen and deepen overtime, eroding all or most of the recognizable features associated with their original construction. As study area was chosen a relatively straight section of the Vecht between two former lakes. Two approaches were used. The first approach centred upon mapping channel morphology and recording sediment stratigraphy of the river deposits through detailed auger coring. Results corroborated the hypothesis of an originally straight feature (landform), confirming that it might have started life as a dug course, but not providing preserved archaeological remains of this stage. The second approach was chronological, whereby a programme of 14C dating was undertaken to refine the understanding of the origin and development of this reach of the Vecht, allowing earlier chronological investigations to be further contextualised and reassessed. A significant challenge to understand age control and floodplain evolution is the degradation of the top of the clayey peat that was observed below the levee deposits; this degradation is due to the lowering of groundwater levels and causes the end of peat growth to be dated as older than it actually is. Using new radiocarbon dates we have reconstructed that the Overmeer-Nigtevecht reach of the Vecht between two former lakes started life as a straight channel. We have constrained its age to be closer to the time of Drusus' activities (early Roman age). Although we have not found in situ remains of Drusus canal(s), these two new insights make the Vecht option, effectuated by a series of short canals, more likely to be the Drusus canal(s)

Mass migration through soil exhaustion: Transformation of habitation patterns in the southern Netherlands (1000 BC-500 AD)

Long-term archaeological data gathering in the southern Netherlands may deliver an unprecedented regional comparison that could be exemplary for the Pleistocene sand areas of the Northwest European Plain. On a micro-scale level, it has become clear that Bronze Age (2000–800 BC) and Iron Age (800–12 BC) farmers intensively used the landscape, resulting in a relatively dense distribution pattern of settlements all over the ridges and planes of the cover sand landscape. However, this agricultural use of the landscape—related to the “celtic field” system—led to a process of soil degradation by increased acidification during which Umbric Podzols gradually transformed into Carbic Podzols that could no longer be used as farmland. According to established “models,” this process of “secondary podzolization” particularly affected those sections of the landscape that were dominated by dry sandy soils with a low loam content (loam=clay and silt, between c. 10% and 20%). In the Late Iron Age (250–12 BC), the changing soil conditions resulted in a dramatic shift in the habitation pattern that clearly manifests itself in the Roman period (12 BC–410AD); on the local scale, the habitation moved from the degenerated soils to nearby areas with better soil conditions (higher loam content), which became more densely inhabited now than in the Bronze Age/Early Iron Age (2000–500 BC). The introduction of new land management (in the later Iron Age, and also by Romans) could also have been important for soil degradation. The areas where the Roman period settlements concentrated became also the areas where we can find the early medieval habitation (447–751AD) and where the Plaggic Anthrosols started to develop in the late medieval period (1270–1500AD). This paper is based on the analysis of soil properties.  Measured loam values of soil samples (n=181) in Veldhoven, southern Netherlands, are in agreement with the described model that the plaggen cover is located on soils containing high combined silt and clay content (>25%) and that Carbic Podzols with no plaggen cover have low combined silt and clay content (<15%). Local spatial as well as vertical variations in loam content of sand layers have shown to occur, warning against single parameter research. Other potential causes for the deviation of the model are as follows: (a) impact of fluctuating groundwater levels; (b) impact of different hydrological properties in the shallow subsurface, depending on the grain size and transmissivity of the sediments; (c) organic matter content; (d) land management; and (e) climate change

Geoarchaeological prospection for Roman waterworks near the late Holocene Rhine-Waal delta bifurcation, the Netherlands

Romans who settled in the Low Countries at the northern margin of their empire were practicing diverse systems of water management to maintain economic and above all strategic stability. In the early Roman period (12BC–AD 70) they created a shipping route from the Rhine towards the north by digging canals and constructing dams, such as the Dam of Drusus, accompanied by the adjacent Roman fortress of Carvium (Herwen). This dam was situated at the bifurcation point of the Rhine and Waal river branches and was designed to channel more water into the Rhine. All these engineering feats were undertaken in order to control the northern part of Germania via the Wadden Sea and the German rivers Ems, Weser and Elbe. By the middle Roman period (AD 70–270) the Romans had cancelled their efforts to subdue Germania and this is a period when the Rhine is known as the limes (Roman state border).  The research area described in this paper is situated near Herwen in the eastern part of the Rhine–Meuse delta system. The area has a dynamic late Holocene erosional and depositional history, close to the river system's equilibrium point. In order to reconstruct the former landscape and to investigate whether evidence of Roman waterworks could be detected, geoarchaeological coring campaigns were carried out to gain insight into the sedimentology, chronology, stratigraphy and geoarchaeology of the region.  Results indicate that Pleistocene sediments are only preserved in the western part of the research area, but further east then previously known. Dating of gullies and levees has confirmed Roman and potentially pre-Roman fluvial activity closer to the Roman fortress of Carvium then was previously known. Four newly discovered residual gullies provide a greater insight into the character of the Roman landscape than hitherto known.  The largest of the newly identified gullies may be instrumental in finding the location of the Dam of Drusus, however, much depends on the question as to whether the gully represents an actual former stream channel or simply a crevasse and this cannot be ascertained on the current evidence. Nevertheless the results of this study reinforce the assumption that the Roman castellum was situated on the apex of the Insula Batavorum and close to the Dam of Drusus at the bifurcation of the Rhine and Waal