Dendrochronology in suboptimal conditions: tree rings from medieval oak from Flanders (Belgium) as dating tools and archives of past forest management

Throughout the Middle Ages forests in Flanders (northern Belgium) experienced a dramatic human influence. Forests were logged for wood supply and converted to arable land. The structure of the remaining forests was altered. This, combined with the tempering influence of the Atlantic climate, results in conditions that are suboptimal for dendrochronological research. Tree-ring series of Quercus robur and Q. petraea of timber from medieval archaeological sites are often short, show abrupt growth-rate variations and are complacent. The question arises whether tree-ring series of this type are potential records of past management and whether they could constitute the basis of a reference chronology for archaeological dating. During six archaeological excavations in and around the medieval town of Ypres, cross-sections were collected. The tree-ring series could be dated back to the 12th–14th centuries, using reference chronologies from surrounding regions. The growth pattern of the short sequences displays a high similarity to tree-ring series from modern coppice. For the first time, it has been confirmed that dendrochronological analysis in Flanders is possible and can provide valuable information on medieval forest use and structure.     

Ossicular density in golden moles (Chrysochloridae)

The densities of middle ear ossicles of golden moles (family Chrysochloridae, order Afrosoricida) were measured using the buoyancy method. The internal structure of the malleus was examined by high-resolution computed tomography, and solid-state NMR was used to determine relative phosphorus content. The malleus density of the desert golden mole Eremitalpa granti (2.44 g/cm³) was found to be higher than that reported in the literature for any other terrestrial mammal, whereas the ossicles of other golden mole species are not unusually dense. The increased density in Eremitalpa mallei is apparently related both to a relative paucity of internal vascularization and to a high level of mineralization. This high density is expected to augment inertial bone conduction, used for the detection of seismic vibrations, while limiting the skull modifications needed to accommodate the disproportionately large malleus. The mallei of the two subspecies of E. granti, E. g. granti and E. g. namibensis, were found to differ considerably from one another in both size and shape.     

Ossicular differentiation of airborne and seismic stimuli in the Cape golden mole (Chrysochloris asiatica)

Comparison between the middle ear anatomy of the Cape golden mole (Chrysochloris asiatica), which exhibits a club-shaped malleus head, and the Desert golden mole (Eremitalpa granti), with a ball-shaped malleus head, suggests differences in sensitivity to airborne sound. Scanning laser Doppler vibrometric measurements of the ossicular behavior in response to both vibration and airborne sound were made in C. asiatica. Two distinct vibrational modes were observed. In response to low-frequency vibration (70–200 Hz), the malleus oscillates about the ligament of the short process of the incus, whereas in response to high-frequency airborne sound (1–6 kHz) the ossicular chain rotates about the long axis of malleus. It is proposed that the club-shaped malleus head in C. asiatica constitutes an adaptation towards bimodal hearing—sensitivity to substrate vibrations and airborne sound. Possible functional differences between these two middle ear types are discussed.     

Revision of Hyolitha from the Ordovician of Estonia

Topotype specimens of the Middle OrdovicianHyolithes acutus Eichwald, 1840, which is the type of the genus that lent its name to a family, order, class, and even phylum according to some, andH. latus Eichwald, 1860 allow that genus and those species to be firmly established on a sound, morphologic basis. In addition, preservation of the types ofHyolithes striatus Eichwald, 1860 is sufficiently good to warrant reassignment toDorsolinevitus Syssoiev, 1958. In contrast, the type ofH. insularis Eichwald, 1860 is incompletely preserved, and this species is not recognizable beyond the type material. The concept of the family Hyolithidae is revised to more closely conform to the morphology ofHyolithes, with authorship herein ascribed toSyssoiev (1958) rather than toNicholson (1872). The stratigraphic distribution of these taxa suggests thatHyolithes as defined herein first appears in the Middle Ordovician, but extends into at least the Lower Devonian, as suggested by two species from the Barrandian region of the Czech Republic. Their geographic distribution further re-enforces the notion of two distinct paleobiogeographic provinces based on hyoliths, a Mediterranean province and Baltic province, with almost no mixing of hyolith faunas during the Ordovician.      

Brachiopods of the family ambocoeliidae (spiriferida) from the givetian of southern Verkhoyansk Region (northeastern Russia)

Four new ambocoeliid species, Ambocoelia ectypa sp. nov., Echinocoelia tikhiensis sp. nov., Emanuella takwanensis (Kayser), and Ladjia sita sp. nov., from the Givetian of the southern Verkhoyansk Region are described (northeastern Russia).     

Itatodon tatarinovi (Tegotheriidae, Mammalia), a docodont from the Middle Jurassic of Western Siberia and phylogenetic analysis of Docodonta

Itatodon tatarinovi Lopatin et Averianov, 2005 is represented by two lower molars and a lower molar fragment from the upper part of the Itat Formation (Bathonian Stage) of the Berezovskii quarry (southern Krasnoyarsk Region). Based on the presence of a pseudotalonid, bordered by the crests a-b, b-e, e-g, and a-g, Itatodon is assigned to the endemic Asian family Tegotheriidae. In this genus, the crest a-b is reduced and the thick lingual cingulid is better developed than that of other docodonts. Phylogenetic analysis of Docodonta shows paraphyly of Morganucodonta relative to docodonts and independent development of the pseudotalonid in the Tegotheriidae and the clade comprising Krusatodon, Castorocauda, Cyrtlatherium, and Dsungarodon.     

Calcareous nannofossil biostratigraphic framework for middle Eocene sediments from ODP Hole 1260A, Demerara Rise

Ocean Drilling Program (ODP) Site 1260 recovered a near-continuous and expanded (187-m thick) middle Eocene carbonate sequence at mid-bathyal depths on Demerara Rise off Suriname, South America. A calcareous nannofossil biostratigraphic framework has been established for the sequence to aid multi-proxy cyclostratigraphic analyses. The diversity of calcareous nannofossils is reasonably high and preservation moderate throughout most of the section, and the proximity to the continent is indicated by the occurrence of braarudosphaerids in the lower three quarters of the section. The species richness of sphenoliths is particularly high, and our data confirm the occurrence of new sphenoliths during the middle Eocene as shown recently by Bown and Dunkley Jones (2006). In particular we corroborate the occurrences of Sphenolithus strigosus and S. runus that these authors found in their Zone NP16 Tanzania sediments, however we extend the ranges of these taxa down into Zone NP15 (CP13). Moreover we document the occurrence of Bramletteius serraculoides in Zone NP15 (CP13b) and the occurrence of Sphenolithus predistentus in NP16 (CP14a), extending their known ranges down column.     

Faunal remains from Porc-Epic: paleoecological and zooarchaeological investigations from a Middle Stone Age site in southeastern Ethiopia

The Middle Stone Age (MSA) sediments of Porc-Epic Cave near Dire Dawa, Ethiopia, have produced a large assemblage of archaeofaunal remains dating to the later periods of the Late Pleistocene. As one of the few MSA faunal assemblages from East Africa subject to detailed analysis, it provides rare insight into the foraging behavior of the early modern humans in this region. The MSA fauna include taxa that were not historically present in the area, with the occurrence of reduncines and alcelaphines indicating widespread grasslands and proximity to a perennial source of water. The faunal analysis examined several lines of evidence, including breakage patterns, surface modification, and skeletal-element representation. By incorporating comparisons with multiple actualistic data sets, the analysis of the assemblage demonstrates that, while the influence of carnivores and other biotic agents was evident, the faunal remains were accumulated primarily by hominid activity. The skeletal-element representation at Porc-Epic includes an abundance of high utility bones, in contrast to the predominance of "head-and-foot" elements documented at other MSA and Middle Paleolithic (MP) sites. The MSA occupants of Porc-Epic effectively exploited a wide range of prey with more emphasis on small- and medium-sized mammals.     

Extending the chronology of deposits at Blombos Cave, South Africa, back to 140 ka using optical dating of single and multiple grains of quartz

Optically stimulated luminescence (OSL) measurements are reported for both single aliquots (of two different sizes) and single grains of quartz from deposits within Blombos Cave. Ages have been obtained for six sediments from the Middle Stone Age (MSA) occupation levels and for two sterile sands, one underlying the archaeological sediment and one overlying the Later Stone Age occupation levels. The ages for the archaeological sediments were obtained from single-grain measurements that enabled unrepresentative grains to be rejected. The MSA occupation levels have ages that, within error limits, are in stratigraphic order and fall between the OSL age for the oldest dune sand (143.2+/-5.5 ka) and a previously published OSL age for the sterile sand ( approximately 70 ka) that separates the Middle and Later Stone Age deposits. The earliest MSA archaeological phase, M3, from where fragments of ochre were found as well as human teeth, is dated to 98.9+/-4.5 ka, coinciding with the sea-level high of oxygen isotope substage 5c. The cave then appears to be unoccupied until oxygen isotope substage 5a on the basis of four OSL ages for archaeological phase M2, ranging from 84.6+/-5.8 to 76.8+/-3.1 ka; these levels contained large hearths and bone tools. An age of 72.7+/-3.1 ka was obtained for the final MSA archaeological phase, M1, from which deliberately engraved ochre and shell beads were recovered along with bifacial stone points. We conclude that the periods of occupation were determined by changes in sea level, with abundant sources of seafood available in times of high sea level and with the cave being closed by the accumulation of large dunes during periods of low sea level, such as during oxygen isotope stages 4 and 6.     

The long arm of the Arab state

ABSTRACT

Under what conditions do authoritarian states exercise control over populations abroad? The securitization of cross-border mobility has been a common theme in examining immigration policies in the Global North. The securitization of emigration and diasporas in non-democratic contexts remains neglected; this is particularly true with regard to Arab states’ extraterritorial authoritarian practices. This article argues that authoritarian states develop a range of migration policies that are driven by the contradictory pressures of economic and political imperatives or, put differently, an illiberal paradox: if a state does not expect economic gains from cross-border mobility, it is more likely to securitize its emigration policy; otherwise, it is more likely to securitize its diaspora policy. The article illustrates this trade-off via a most-similar comparison of Algeria, Libya, Tunisia, and Morocco. Drawing on Arabic and non-Arabic primary and secondary sources, it sketches a novel area of research on migration and security.