Understanding Of Taphonomic Processes Research Articles

A tale of multi-proxies: integrating macro- and microbotanical remains to understand subsistence strategies

The integrated analysis of several proxies in order to answer a research question is a widespread approach in palaeoecology, but it is not well developed in archaeobotanical research. Applying a multi-proxy approach to archaeobotany has several advantages: a more diverse anatomical and taxonomical representation of the original plant input and a better understanding of taphonomic processes, both depositional and post-depositional. The aim of this paper is to show how a multi-proxy approach can enrich our understanding of plant-related subsistence strategies. Macro and microbotanical analyses were carried out on samples from Shikarpur, a Chalcolithic settlement in Kachchh, Gujarat, northwest India. This settlement is located in a semi-arid region with wet/dry cycles and highly saline soils that influence the preservation of charred remains, so that they do not offer the full picture of plant-related subsistence strategies. We show that the combination of different proxies is crucial to cross-validate the results and to gain a wider understanding of plant use strategies. The inhabitants of Shikarpur relied on a double-cropping system based on local small millets and pulses, and they also consumed cereals, tubers and sedges.

The southern North Sea and the human occupation of northwest Europe after the Last Glacial Maximum

AbstractThis paper discusses the significance of the southern North Sea for research on the human occupation of northwest Europe after the Last Glacial Maximum (LGM). Recent insight into the survival of post-LGM land surfaces and palaeolandscape structures points to the potential preservation of Late Palaeolithic and Mesolithic sites in this area. Finds of well-preserved materials (including artefacts of bone, antler and wood, as well as human remains) from various zones along the Dutch and British coasts corroborate this idea, whilst underwater excavations of eroding sites at Bouldnor Cliff (UK) and Maasvlakte-Rotterdam (NL) underpin the possibilities of gaining further insight into human behaviour in the context of submerging landscapes. Although the significance of the southern North Sea with regard to the Mesolithic is gradually exposed, there is still a lot to learn. The terrestrial archaeological records from both sides of the present-day North Sea yield indisputable evidence for hunter-gatherer presence from at least 13,000 BP. Successions of Magdalenian/Creswellian/Hamburgian, Federmesser Gruppen and Ahrensburgian people (re)colonised the northwest European plain, interrupted by short-lived cold spells. Although it is expected that the southern North Sea must have been inhabited, and maybe even more intensively than the present-day dry land, archaeological evidence is still missing. Despite the presence of vast amounts of mammalian remains and the availability of many radiocarbon-dated bones, there is a striking lack of material post-dating the LGM and pre-dating the Holocene, whilst remains dated to the early Upper Palaeolithic show no evidence of human interference. At this stage, it is probable that taphonomic factors and research biases are responsible for this picture. This marks a sharp contrast with the early Holocene record, where numerous Mesolithic artefacts, as well as human remains, provide evidence for human occupation of the area. Materials are exposed on the sea floor, evidencing gradual erosion of early Holocene land surfaces. Although the number of sites is increasing, little is known yet about how the submerged record can be connected to the terrestrial record. Indeed, the central question here is how the submerged Mesolithic record compares to, or differs from, the terrestrial record. In order to answer this question, targeted archaeological research is needed, along with an understanding of taphonomic processes and increased insight into landscape dynamics. From a northwest European perspective, the present state of knowledge about the submerged post-LGM prehistoric archaeology of the southern North Sea demonstrates its huge research potential.

Experiments in Taphonomy

Several long-term taphonomic experiments are described with the aim of providing comparative data with which to interpret palaeontological and archaeological sites. The study of taphonomy is an adjunct to site interpretation, especially the reconstruction of palaeoecology, and an understanding of taphonomic processes can only come about through actualistic and laboratory analyses. Experiments described include the Overton Down earthworks (32-year-old buried bone); trampled bone from Draycott (17 years old); weathered amphibian bone also from Draycott (16 years old); surface-weathered bone from Arabia (following 10 years' exposure); bone dispersal, weathering, burial, burning, and scavenging in Rhulen, Wales (with many skeletons ranging from 1 to 20 years old); and finally a series of laboratory experiments set up to test particular processes. These included earthworm activity, abrasion, breakage, and predation on small mammals. Two examples are given at the end to show how the effects of these processes can be identified in the past, and how their identification can help to resolve particular issues in two palaeontological sites. These are the middle Pleistocene deposits at Westbury-sub-Mendip, Somerset, and middle Miocene deposits at Pasalar, Turkey.

Cells and tissues in the vegetative sporophytes of early land plants.

Remarkable preservation in coalified and pennineralized fossils from Upper Silurian and Lower Devonian sediments deposited some 420 to 390 million years ago provides insight into the major anatomical innovations associated with the early stages in the colonization of the land by higher plants. Using uniformitarian principles, such information, combined with gross morphology, can then be used to reconstruct the pioneers as growing, metabolizing and reproducing organisms, as well as allowing assessment of affinity, although apart from the lycophytes, they have no close relationship with extant groups. In considering vascular tissues, diversity is exemplified by descriptions of the metaxylem in protosteles of Zosterophyllopsida and Drepanophycopsida (putative lycophytes), of Psilophyton (Trimerophytopsida), of the Rhyniaceae (including Rhynia gwynnevaughanii, certain Taeniocrada spp., Sennicaulis) and of Cooksonia pertoni, a Lower Devonian representative of the organization found in the oldest pteridophyte-like land plants. Aglaophyton major is included as a plant with bryophyte-like vascular tissues in a branching sporophyte with cuticle, stomata and intercellular space system typical of the homoiohydric tracheophyte. In all water-conducting cells, interpretation of the primary and secondary wall results from comparisons involving the anatomy and chemistry of extant examples and an understanding of taphonomic processes. Phloem is only rarely preserved and usually identified from its position around the xylem. In contrast, dermal features are better known, because of penetration of the resilient cuticle between epidermal cells. They appear conservative. Thus stomata with two guard cells look remarkably similar to extant forms in surface view, and by consideration of their relationship with surrounding epidermal cells and of extent of cuticularization, seem to have operated in a similar way to those in certain mosses and ferns. Cuticular ornamentation (papillae, striations) and epidermal outgrowths (unicellular and multicellular) are described and their adaptive significance conjectured. Ground tissue systems are best preserved in Rhynie Chert permineralizations where zonation of the cortex is tentatively related to photosynthetic and structural roles. The latter function is also attributed to thick-walled, outer cortical cells recorded in many zosterophylls and in Psilophyton, although the chemical nature of the walls themselves remains equivocal. Problems of identification of roots in plants possessing axial organization with exarch xylem, and in leafy plants with smooth lateral branching systems are briefly addressed. Finally axis apices in Rhynia givynne-vaughanii and sections showing stages in the maturation of Asteroxylon stems are described from the Rhynie Chert. Contents Summary 225 I. Introduction 226 II. Vascular systems 226 III. Dermal systems 237 IV. Ground tissue systems 241 V. Apical meristems 244 VI. Distinction of aerial stems, rhizomes and roots 245 VII. Why anatomy? 245 Acknowledgements 245 References 245.