Lopingian (Upper Permian) trace fossils from the northern Penglaitan Section,Laibin, Guangxi,South China and their environmental implications

The end-Permian mass extinction has been widely documented to be accompanied with oceanic anoxia, which was considered as one of the most plausible killing mechanisms. However, it is still unclear when anoxia began to occur and how widely affected during the pre-extinction interval. In this study, Lopingian bottom-water oxygen level changes around the Wuchiapingian–Changhsingian boundary (WCB) at the northern Penglaitan section in Guangxi are analysed based on trace fossil assemblages and ichnofabric indices. Detailed bed-by-bed ichnological analyses confirm the presence of trace fossils Chondrites intricatus, C. isp., Palaeophycus isp., Planolites isp. A, P. isp. B, Thalassinoides isp. A, T. isp. B, Trichichnus linearis, Zoophycos isp., and other bioturbational structures. The ichnofabric indices around the WCB are mostly 1–2, but rapidly increase to 4–5 in some short intervals. The distinct fluctuations of ichnofabric indices suggest that the oxygen level of sediments was generally deficient, but the dysoxic or anoxic periods were punctuated by several short oxic intervals. Thus, it can be inferred that the benthic organisms were under secularly environmental stresses around the WCB at the northern Penglaitan section. The anoxic conditions unfavourable for aerobiosis in the deep basin may start in the late Wuchiapingian. However, more sections need to be studied to determine whether this is a local or regional phenomenon.     

Evidence for plant exploitation and vegetation history from three Early Neolithic pre-pottery sites on the Euphrates (Syria)

Archaeobotanical results based on a limited number of samples from three aceramic sites dating from 9800 to 7800 B.P., which are under excavation in the valley of the Middle Euphrates, are discussed. The finds are presented simply by presence, and are compared to the contemporary vegetation and finds from similar sites. Carbonised plant remains recovered by flotation from levels dated to between 9800 and 9200 B.P. (Dja'de and Jerf al Ahmar) indicate that wild cereals (einkorn wheat, rye and barley) and pulses (lentils, pea and bitter vetch) were exploited. Other plants such as wild grasses, Pistacia, wild almond and oak, suggest that the local vegetation provided a rich diversity of resources. A study of possible weed taxa is being carried out in order to see whether this assemblage could be used to identify the cultivation of morphologically wild cereals for this period. Ninth millennium B.P. levels at Halula see the appearance of domestic crops such as emmer, naked wheat and barley, but wild-type cereals persist. The cultivars appear to have been introduced from elsewhere and later ninth millennium B.P. species include olive and flax. Ash, vine, maple, plane, alder and elm from the gallery forest, wild rye, wild einkorn, deciduous oak, wild almond, Pistacia, and Pyrus, from the hinterland, indicate cooler conditions.     

Evolution of South American mammalian predators (Borhyaenoidea): anatomical and palaeobiological implications

The evolution of South American carnivorous marsupials, the borhyaenoids, has been investigated through the functional analysis of postcranial adaptive traits and palaeobiological data. There is evidence that the evolutionary history of Borhyaenoidea proceeded from a noncursorial ancestor. The locomotion and habits of the early Palaeocene Mayulestes ferox probably approached a generalized plesiomorphic pattern for marsupial locomotion, i.e. primarily terrestrial with secondary arboreal adaptations. An exceptionally rich early Miocene Patagonian fauna has yielded various morphological predator types, from scansorial ambusher to terrestrial, incipiently cursorial, taxa. The most specialized borhyaenoid was the powerful sabretooth Thylacosmilus atrox that survived until the late Pliocene. The evolution from a scansorial pattern towards a cursorial trend, illustrated by Borhyaena tuberata , and towards the probable development of postlactational parental care in Thylacosmilus , required by its dental specialization and killing strategy, suggests a modification of the selective pressures and predatory activities of the group over evolutionary time.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 140 , 487–521.     

Types of the cerebral arterial circle (circle of Willis) in a Sri Lankan Population

Background  

The variations of the circle of Willis (CW) are clinically important as patients with effective collateral circulations have a lower risk of transient ischemic attack and stroke than those with ineffective collaterals. The aim of the present cadaveric study was to investigate the anatomical variations of the CW and to compare the frequency of prevalence of the different variations with previous autopsy studies as variations in the anatomy of the CW as a whole have not been studied in the Indian subcontinent.     

Protein variation and its systematic implications for the South African Leporidae (Mammalia:Lagomorpha)

Analysis of 9 genetic loci by horizontal starch gel electrophoresis was performed on 203 specimens of South African representatives of the leporid genera Lepus and Pronolagus . Three loci were found to be polymorphic within samples of the various species of both genera: transferrin (Tf-I), esterase-1 (Es-I) and esterase-2 (Es-II). Only one system, carbonic anhydrase (CA-I), proved useful in species identification, this being restricted to the genus Lepus . Based on this system all Lepus specimens analysed would be assigned to one of two groups corresponding to the species L. capensis and L. saxatils .     

Protein variation and its systematic implications for the South African Leporidae (Mammalia:Lagomorpha)

Analysis of 9 genetic loci by horizontal starch gel electrophoresis was performed on 203 specimens of South African representatives of the leporid genera Lepus and Pronolagus. Three loci were found to be polymorphic within samples of the various species of both genera: transferrin (Tf-I), esterase-1 (Es-I) and esterase-2 (Es-II). Only one system, carbonic anhydrase (CA-I), proved useful in species identification, this being restricted to the genus Lepus. Based on this system all Lepus specimens analysed would be assigned to one of two groups corresponding to the species L. capensis and L. saxatilis.     

Palaeoenvironmental and biostratigraphical implications of selected Floian and Dapingian (Ordovician) chitinozoans of the South China Palaeoplate

Chitinozoans are widespread microfossils in the Ordovician to Devonian strata. Although they have been widely adopted in biostratigraphy, their environmental preferences are rarely discussed. In this study, the palaeoecological distribution of four Floian and Dapingian key chitinozoans in six coeval stratigraphical units based on 13 sections from the South China Palaeoplate is discussed in detail, including Bursachitina maotaiensis (Chen 2009a), Bursachitina qianbeiensis (Chen 2009a), Conochitina decipiens and Sagenachitina dapingensis (Chen 2009b). It appears that B. maotaiensis and B. qianbeiensis preferred inner shelf environments and could spread to near‐shore and shallow outer shelf settings. C. decipiens mostly favoured inner shelf and shallow outer shelf environments. S. dapingensis had the widest environmental tolerance and was adapted to almost all environments, with the exception of the near‐shore area on the Yangtze Platform. Biostratigraphically, the four species have relatively well‐constrained ranges, and their first appearances provide good bases for regional correlations. The endemic B. maotaiensis and B. qianbeiensis can be good markers for the upper Floian, but their relatively narrow environmental preferences should be taken into account. S. dapingensis proves to be a good marker for the Dapingian in the South China Palaeoplate, except in the near‐shore areas. The globally distributed C. decipiens also has a biostratigraphical significance in most areas of the Yangtze Platform. Our study indicates that well‐documented environmental preferences of key species help to provide more reliable and practical biostratigraphical correlations.     

Enthesopathies (lesions of muscular insertions) as indicators of the activities of neolithic Saharan populations

Enthesopathies are bony lesions involving the sites of insertion of muscles or ligaments. Those caused by hyperactivity of the relevant muscles may be distinguished clearly from those of metabolic or inflammatory origin. Observations from sporting and occupational medicine indicate that specific enthesopathies are correlated with different activities. Examination of the enthesopathies present on two groups of well-preserved neolithic skeletons from separate regions of the Sahara with different paleoenvironments show that overall 20% of the skeletons presented lesions. Three different forms of enthesopathy involved the arm, principally the elbow, and may be tentatively correlated with javelin throwing, wood cutting, and archery. Two types of lesion involving the foot were observed in skeletons from a hunter-gatherer population and may be correlated with much walking or running over hard ground. I suggest that the analysis of such lesions on ancient skeletons may, in concert with other archaeological data, throw light on the activities of ancient people.     

Social and environmental impacts on sleep in captive Asian elephants (Elephas maximus)

Modern zoos strive to improve standards of animal management, husbandry and welfare of their animals as part of a continual evaluation process. Elephants (Elephantidae) have received particular attention in recent years due to the challenge of providing environments which promote natural behavior and opportunities for social interaction. A number of measures have been proposed to measure wellbeing, with sleep quality increasingly being used. Sleep is a vital aspect of life for cell replenishment as well as optimal development of young. Sleep deprivation can lead to immunosuppression and illness; therefore animal managers have a responsibility to ensure they reduce the potential for disturbance through noise, light, or other environmental factors. The social environment also plays an essential role in wellbeing, particularly for species that live in multi-generational family units. In this study the nocturnal behavior of a multi-generational captive herd was observed to determine impacts of husbandry changes on sleep duration and bout length (measured as recumbent rest). As expected, average total duration of sleep was higher in younger elephants and rates were comparable to those reported in other studies of Asian elephants. Overnight access to an outdoor paddock in warmer weather increased overall average bout length of sleep in the herd. Average total duration of sleep also increased for the herd following the movement of an unrelated adult female who had previously shown weak bonds with other herd members. This indicates that social compatibility is a vital component of elephant welfare, impacting not only behavioral interactions but sleep quality and duration.     

Diet and health changes at the end of the Chinese neolithic: the Yangshao/Longshan transition in Shaanxi province.

In this paper we discuss diet and health changes of millet agriculturists in Northern China, Shaanxi province, during the period 7,000-4,000 BP. An episode of intensive climatic oscillations that preceded the onset of colder climate circa the fifth millennium BP divides the period (Shi et al. [1993] Global Planet. Change 7:219-233). The onset of the cooler climate marks the decline of the egalitarian society of Yangshao and the rise of the chiefdom-like society of Longshan. Skeletal materials from the two sites of Beiliu and Jiangzhai are from the earlier phases of Yangshao culture (7,000-6,000 BP), while remains from the Shijia site were excavated from the terminal phase of Yangshao culture (6,000-5,000 BP), a phase that would be expected to show adjustments to strong climatic fluctuations. Human remains from the Longshan culture (5,000-4,000, BP) were found at the Kangjia site. In order to investigate whether the trajectory of diet and health changes persisted beyond the Longshan, a skeletal sample from the Xicun site of the Western Zhao Dynastic period (3,800-2,200 BP) is included in our analyses. All Yangshao sites in our study are characterized by low frequencies of anemia and carious lesions. Some subsistence changes probably occurred during the later phase of Yangshao culture that resulted in elevated masticatory stress and occlusal macrowear among the Shijia people. However, deterioration of community health did not begin until the Longshan, when increased occurrence of porotic hyperostosis and caries is accompanied by decreased adult stature. The transition to softer, more extensively processed food during Longshan is evident in decreased rates of occlusal wear. Increased population density and diminished food values were most likely responsible for these changes. Poor health persisted into the subsequent Dynastic period of Western Zhao.     

Social relationships between immigrant and resident bonobo (Pan paniscus) females at Wamba.

Social relations and behaviours of adolescent female pygmy chimpanzees (Pan paniscus) that migrated between unit groups were studied at Wamba, Za?re. Each immigrant female selected one particular resident female, a 'specific senior female' (SSF) and frequently approached and followed her. Affinitive behaviours (e.g. grooming, genitogenital rubbing) were frequently performed between the immigrant and her SSF. Most affinitive behaviours were more likely to be initiated by the immigrant than by her SSF. The immigrant's relationship with her SSF seemed to facilitate the immigrant's integration into the new unit group. Resident males actively approached and mated with the immigrant females. Copulation also appeared to further the immigrant's stable relationship with the resident males.     

Shallow environmental gradients put inland species at risk: Insights and implications from predicting future distributions of Eucalyptus species in South Western Australia

As climate changes, tree decline in Mediterranean‐type ecosystems is increasing worldwide, often due to decreased effective precipitation and increased drought and heat stress, and has recently been observed in coastal species of the iconic Eucalyptus (Myrtaceae) genus in the biodiversity hotspot of south‐west Western Australia. To investigate how this drought‐related decline is likely to continue in the future, we used species distribution modelling techniques to generate broad‐scale predictions of future distribution patterns under three distinct projected climate change scenarios. In a moderate climate change scenario, suitable habitat for all species was predicted to decrease by, on average, 73% by the year 2100, with most receding into southern areas of their current distribution. Although the most severe Eucalyptus declines in south‐west Western Australia have been observed in near‐coastal regions, our predictions suggest that inland species are at greater risk from climate change, with six inland species predicted to lose 95% of their suitable habitat in a moderate change scenario. This is due to the shallow environmental gradients of inland regions causing larger spatial shifts of environmental envelopes, which is likely to be relevant in many regions of the world. The knowledge gained suggests that future research and conservation efforts in south‐west Western Australia and elsewhere should avoid focussing disproportionately on coastal regions for reasons of convenience and proximity to population centres, and properly address the inland region where the biggest future impacts may occur.     

The influence of environmental changes on local and regional vegetation patterns at Rieme (NW Belgium): implications for Final Palaeolithic habitation

Late-glacial vegetation changes were studied at Rieme, NW Belgium. Human occupation of this cover sand area occurred from the Final Palaeolithic onwards. The research area is situated on the northern side of a large cover sand ridge in an undulating landscape with small ridges and depressions. The past landscape was reconstructed using a multi-disciplinary approach, including geomorphological, sedimentological, loss-on-ignition, botanical (micro- and macrofossil) and zoological analyses. AMS ¹⁴C dating provided an accurate chronology for the sediments. Analyses were performed on three sequences located ~200?C300?m apart. Our study shows that during the B?lling (GI-1e) wet meadows developed on the sandy soils and groundwater levels increased probably as result of permafrost melting. Shallow pools formed in depressions. During the Older Dryas (GI-1d) shrubs with juniper, sea-buckthorn and willow developed. Many shallow depressions were overblown with sand and deposition of organic material almost ceased. In the early Aller?d (GI-1c) open birch woodlands developed. Due to the final melting of permafrost, groundwater levels rose further and ponds with floating-leaved open water vegetation developed. Large water level fluctuations occurred in one of the ponds. Accumulation of organic deposits ceased during the mid-Aller?d. Indirect evidence for human occupation during the Aller?d (GI-1c) was found in indications of burning of the reed-swamps in combination with the presence of large herbivores. Final Palaeolithic people probably used the northern side of the cover sand ridge as hunting area, while they settled their temporary (base) camps on the steep southern side along the extensive and deeper Moervaart lake.     

Dietary reconstruction of the Amphipithecidae (Primates, Anthropoidea) from the Paleogene of South Asia and paleoecological implications

The primate family, Amphipithecidae, lived during the early Cenozoic in South Asia. In this study, the diet of late middle Eocene amphipithecids from the Pondaung Formation (Central Myanmar) is characterized using three different approaches: body mass estimation, shearing quotient quantification and dental microwear analysis. Our results are compared with other Paleogene amphipithecids from Thailand and Pakistan, and to the other members of the primate community from the Pondaung Formation. Our results indicate a majority of frugivores within this primate community. Pondaungia and “Amphipithecus” included hard objects, such as seeds and nuts, in their diet. Folivory is secondary for these taxa. Myanmarpithecus probably had a mixed diet based on fruit and leaves. Contrasting results and a unique dental morphology distinguish Ganlea from other amphipithecids. These render interpretation difficult but nevertheless indicate a diet tending towards leaves and fruit. However, the anterior dentition of Ganlea suggests that this taxon engaged in seed predation, using its protruding canine as a tool to husk hard fruits and obtain the soft seeds inside. Bahinia and Paukkaungia, two other Pondaung primates, are small (<500 g) and therefore would have depended on insects as their source of protein. As such, they occupied a very different ecological niche from Pondaung amphipithecids. This primate community is then compared with the Eocene-Oligocene primate communities of the Fayum from North Africa. Similarities between the late middle Eocene Pondaung primate community and extant equatorial and tropical South American primate communities are noted.     

Species limits and morphometric and environmental variation within the South Andean and Patagonian Mulinum spinosum species-group (Apiaceae-Azorelloideae)

Delimiting species is an important, but frequently difficult aspect of systematics that should be addressed using data from multiple sources. Here we combine morphometric analyses and environmental characteristics to delimit species in the South Andean and Patagonian taxonomically difficult species-group composed by Mulinum spinosum, M. echinus and M. leptacanthum (Apiaceae-Azorelloideae). Molecular phylogenies have shown that these three species form part of a polytomy together with other Mulinum species, and therefore these data are not useful for their delimitation. We include measurements of 25 morphometric variables from 163 herbarium specimens and perform univariate and multivariate principal component analysis (PCA) and discriminant analysis (DA) to establish the limits amongst the three mostly sympatric, morphologically similar, and phylogenetically unresolved species. We also use 19 bioclimatic and three geographic variables from localities of the specimens to infer environmental characteristics of the taxa and test their relation with morphological variation. Morphological evidence supports the inclusion of M. echinus within the morphologically and climatically variable M. spinosum, and rejects its recognition as a distinct taxon at any rank. On the contrary, M. leptacanthum is considered a morphologically distinct species, generally restricted to high altitude areas of the southern Andes with a cooler and wetter climate. Within the widespread M. spinosum, environmental gradients of precipitation and temperature relate to morphological gradients (e.g., in leaf and inflorescence sizes, in leaf acicularity, and in fruit-wing width). These last results showed that the large morphological variation in vegetative and reproductive characteristics of this species that grows in arid and semiarid habitats are related to regional climatic gradients that have probably been important in the evolution of this species' plasticity, diversification, and differentiation.     

Differentiation at mitochondrial and nuclear loci between the blesbok (Damaliscus pygargus phillipsi) and bontebok (D. p. pygargus): implications for conservation strategy

Damaliscus pygargus is an endemic species in South Africa belonging to the contemporary antelope tribe Alcelaphine. The species has been subdivided into two subspecies based upon phenotypic differences and historical geographic isolation. We found D. p. pygargus (bontebok) and D. p. phillipsi (blesbok) to be significantly differentiated based on microsatellite and mtDNA control region markers. Bontebok genetic diversity was depauperate with just one mtDNA haplotype, not found in blesbok populations, and reduced heterozygosity and polymorphism at microsatellite DNA loci compared to the blesbok. Erosion of molecular genetic variation in bontebok may have been due to anthropogenic impact causing isolation and reduced population size. Our data based on 34 bontebok and 42 blesbok indicate that the classification of alpha taxonomy should be reconsidered in this genus (in support of earlier similar suggestions), and that careful management should seek to avoid hybridization and retain the remaining diversity in the bontebok.