Did the Romans introduce the Egyptian mongoose (<Emphasis Type="Italic">Herpestes ichneumon</Emphasis>) into the Iberian Peninsula?

New finds of bones of the Egyptian Mongoose (Herpestes ichneumon), one from Portugal and one from Spain, were directly ¹⁴C dated to the first century AD. While the Portuguese specimen was found without connection to the Chalcolithic occupation of the Pedra Furada cave where it was recovered, the Spanish find, collected in the city of Mérida, comes from a ritual pit that also contained three human and 40 dog burials. The finds reported here show that the Egyptian mongoose, contrary to the traditional and predominant view, did not first arrive in the Iberian Peninsula during the Muslim occupation of Iberia. Instead, our findings are consistent with the hypothesis that the species was first introduced by the Romans, or at least sometime during the Roman occupation of Hispania. Therefore, radiocarbon dating of new archaeological finds of bones of the Egyptian Mongoose (Herpestes ichneumon) in the Iberian Peninsula push back the confirmed presence of the species in the region by approximately eight centuries, as the previously oldest dated record is from the ninth century. With these new dates, there are now a total of four ¹⁴C dated specimens of Egyptian mongooses from the Iberian Peninsula, and all of these dates fall within the last 2000 years. This offers support for the hypothesis that the presence of the species in Iberia is due to historical introductions and is at odds with a scenario of natural sweepstake dispersal across the Straits of Gibraltar in the Late Pleistocene (126,000–11,700 years ago), recently proposed based on genetic data.     

Paleoenvironmental conditions in the Spanish Miocene–Pliocene boundary: isotopic analyses of Hipparion dental enamel

Expansion of C₄ grasses during Late Miocene and Early Pliocene constitutes one of the most remarkable biotic events of the Cenozoic era. The Teruel–Alfambra region (northeastern Spain) contains one of the most complete Miocene–Pliocene sequences of mammalian fossil sites in the world. In this study, stable isotope (δ ¹³C and δ ¹⁸O) analyses have been performed on the tooth enamel from the equid Hipparion from 19 localities spanning a time interval from approximately 10.9 to 2.7 Ma. This time range starts with the first appearance of this genus in Spain and ends at its extinction. An increase in δ ¹³C at about 4.2 Ma has been observed, indicative of a shift toward a more open habitat. This shift may be related to a large scale vegetation change which occurred across the Miocene–Pliocene boundary when C₄ grasses expanded. This expansion might in turn be linked to global tectonic events such as the uplift of the Himalaya and/or the closure of the Panama Isthmus. However, other more regional factors may have ultimately enhanced the trend toward more open habitats in the Western Mediterranean Basin. The Messinian Salinity Crisis was a major environmental event that may have been responsible for the isotopic changes seen in the equid Hipparion from the Iberian Peninsula along with an increase in the aridity detected ~4.6 Ma ago in the Sahara. Even though the exact factor triggering the isotopic change observed in the Hipparion enamel remains mostly unknown, this study demonstrates that the global environmental changes detected across the Miocene–Pliocene boundary are also recorded in the realm of the Iberian Peninsula. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Geographic variations in seed dispersal by ants: are plant and seed traits decisive?

The effect of local ant species on the dispersal success of a myrmecochorous plant, Helleborus foetidus, was analyzed in two populations of the Iberian Peninsula (Caurel and Cazorla, respectively). The contribution of the various local ant species to dispersal was very unequal. While 5 and 19 ant taxa visited the plants of Caurel and Cazorla, respectively, most removal activity (67 and 80%) was performed by two species only (Formica lugubris and Camponotus cruentatus, respectively). Visits by dispersers were also unequally distributed between neighboring plants. While some plants were always visited during the period of seed release, others were never visited. A regression model indicated that this pattern might be explained by two plant traits: ants preferred to visit plants that released more seeds and whose elaiosomes were richer in oleic acid. Although it has long been known that this compound triggers removal by ants, it is the first demonstration that quantitative variations in elaiosome traits contribute to variation in dispersal success. Finally, other variables being equal, morphological traits (seed size, elaiosome size, and elaiosome/seed size ratio) did not affect ant behavior. Although myrmecochory has long been considered a diffuse interaction, our results support the idea that, at local scale, a limited number of ant species may be decisive to its evolution.     

Bone histology of the titanosaur <Emphasis Type="Italic">Lirainosaurus astibiae</Emphasis> (Dinosauria: Sauropoda) from the Latest Cretaceous of Spain

The titanosaur Lirainosaurus astibiae is the only sauropod species known from the Late Cretaceous of the Iberian Peninsula. Lirainosaurus did not reach a gigantic body size and is one of the smallest sauropods discovered to date. Histological analysis of Lirainosaurus bones, focused on diaphyseal transverse sections of appendicular elements, reveals that Lirainosaurus did not exhibit the osseous microstructure typical for large sauropods, but is comparable with that of the coeval titanosaurs Alamosaurus sanjuanensis, Ampelosaurus atacis, and Magyarosaurus dacus, and also shares histological traits with other small to medium-sized sauropodomorph dinosaurs. Lirainosaurus limb bones exhibit a laminar fibrolamellar bone microstructure interrupted by growth marks, fully obliterated in adulthood by intense secondary remodeling processes which tend to replace completely the primary cortex. Lirainosaurus attained smaller sizes than typical sauropods reducing the rate of primary periosteal osteogenesis and developing an extensive secondary remodeling well before the adult size was reached. Histological organization of Lirainosaurus long bones is more mature than observed in basal neosauropods at similar ontogenetic stage, documenting a case of peramorphosis by pre-displacement. This heterochronic growth would be a reversal of the accelerated pattern of bone deposition typical for the sauropod lineage.     

The earliest occurrence of the steppe pika (Ochotona pusilla) in Europe near the Pliocene/Pleistocene boundary

The steppe pika (Ochotona pusilla), a representative of the lagomorph family Ochotonidae, is restricted today to Kazakhstan and Russia. This subspecies-rich form belongs to a morphologically distinct, monospecific group of relatively small pikas, inhabiting steppe-like habitat. In the fossil record, it serves as a bioindicator of dry, grassland environment. The steppe pika was abundant and widespread in Europe during the Last Glaciation, and its unquestionable presence has been reported there since the middle Pleistocene. A new discovery of O. pusilla, from the Kielniki 3B locality (Poland), dated to the latest Pliocene, moves back the species appearance in Europe about one million years, almost coeval with its first record from the late Pliocene of Kazakhstan. Presence of such a typical steppe inhabitant as O. pusilla indicates significant climate change towards more arid, continental conditions, which started influencing Europe at 2.6 Ma. We present the first reliable record of the earliest O. pusilla entry deep into Europe in the latest Pliocene.     

Contribution of spatially explicit models to climate change adaptation and mitigation plans for a priority forest habitat

Climate change will impact forest ecosystems, their biodiversity and the livelihoods they sustain. Several adaptation and mitigation strategies to counteract climate change impacts have been proposed for these ecosystems. However, effective implementation of such strategies requires a clear understanding of how climate change will influence the future distribution of forest ecosystems. This study uses maximum entropy modelling (MaxEnt) to predict environmentally suitable areas for cork oak (Quercus suber) woodlands, a socio-economically important forest ecosystem protected by the European Union Habitats Directive. Specifically, we use two climate change scenarios to predict changes in environmental suitability across the entire geographical range of the cork oak and in areas where stands were recently established. Up to 40 % of current environmentally suitable areas for cork oak may be lost by 2070, mainly in northern Africa and southern Iberian Peninsula. Almost 90 % of new cork oak stands are predicted to lose suitability by the end of the century, but future plantations can take advantage of increasing suitability in northern Iberian Peninsula and France. The predicted impacts cross-country borders, showing that a multinational strategy, will be required for cork oak woodland adaptation to climate change. Such a strategy must be regionally adjusted, featuring the protection of refugia sites in southern areas and stimulating sustainable forest management in areas that will keep long-term suitability. Afforestation efforts should also be promoted but must consider environmental suitability and land competition issues.     

The oldest African fox (Vulpes riffautae n. sp., Canidae, Carnivora) recovered in late Miocene deposits of the Djurab desert, Chad

We report on the oldest fox (Canidae) ever found in Africa. It is dated to 7 Ma based on the degree of evolution of the whole fauna. It belongs to a new species. Its overall size and some morphological characteristics distinguish the Chadian specimen from all the other foxes. The presence of Vulpes and of the genus Eucyon in slightly younger African locality, as well as in southwestern Europe in the late Miocene, may indicate that canids migrated in Europe from Africa through a trans-Mediterranean route.     

Last Glacial mammals in South America: a new scenario from the Tarija Basin (Bolivia)

The chronology, sedimentary history, and paleoecology of the Tarija Basin (Bolivia), one of the richest Pleistocene mammalian sites in South America, are revised here based on a multidisciplinary study, including stratigraphy, sedimentology, geomorphology, paleontology, isotope geochemistry, and ¹⁴C geochronology. Previous studies have indicated a Middle Pleistocene age for this classic locality. We have been able to obtain a series of ¹⁴C dates encompassing all the fossil-bearing sequences previously studied in the Tarija Basin. The dated layers range in age from about 44,000 to 21,000 radiocarbon years before present (BP), indicating that the Tarija fauna is much younger than previously thought. Glacial advances correlated to marine isotopic stages (MIS) 4 and 2 (ca. 62 and 20 ka BP, respectively) are also documented at the base and at the very top of the Tarija–Padcaya succession, respectively, indicating that the Bolivian Altiplano was not dry but sustained an ice cap during the Last Glacial Maximum. The results of this multidisciplinary study enable us to redefine the chronological limits of the Tarija sequence and of its faunal assemblage and to shift this paleontological, paleoclimatological, and paleoecological framework to the time interval from MIS 4 to MIS 2.     

Dietary characterization of the hominoid Khoratpithecus (Miocene of Thailand): evidence from dental topographic and microwear texture analyses

The genus Khoratpithecus, a hominoid thought to be related to the orangutan lineage, is represented by two known fossil species K. chiangmuanensis and K. piriyai. Both were discovered in Southeast Asia (Thailand) and are dated to the Middle and Late Miocene, respectively. In this study, dental topographic and microwear texture analyses were used to examine molars from both of these species, with the goal of understanding their dietary preferences. Although sample sizes are small for Khoratpithecus, available data are compared to that collected for extant apes. Environmental evidence, such as botanical remains and sedimentological data, is also considered for comparisons with dietary reconstruction. Results from dental topographic analysis suggest that the two fossil species were better adapted to a diet of fruits than to one of leaves, much like the living orangutan or chimpanzee. Results from microwear texture analysis further support this, suggesting that Khoratpithecus preferred soft fruits to hard fruits or seeds. And finally, the botanical and sedimentological evidence point to environments for Khoratpithecus that would have been compatible with a fruit-eating species. Given the small sample sizes available for analysis, however, definitive judgments are not yet possible at this time.     

Determinations of methyl iodide in the Antarctic atmosphere and the south polar sea

Methyl iodide (CH₃I) concentrations were determined in the atmosphere and in surface sea water near the Antarctic Peninsula with a GC/ECD system during October–December 1987. The mean air concentration of methyl iodide was 2.4 pptv with a corresponding seawater concentration of 2.6 ng l⁻¹. In addition chloroiodomethane (CH₂ClI) was detected in some of the seawater samples as a second volatile organoiodine species. No relationship between methyl iodide and biogenic brominated methanes was found. From this it follows that methyl iodide has a different pathway of biogenic production in marine organisms than the brominated methanes. Based on a two-phase model a global sea-to-air flux for methyl iodide of 8 × 10¹¹ g yr⁻¹ was calculated. This is important for the balance of the global biogeochemical iodine cycle assuming that methyl iodide is by far the dominant volatile organoiodine species in the environment.     

春季北京市河流大型底栖动物群落结构特征及影响因子分析

2019年春季(3～5月)在北京市开展了17个水体20个断面的大型底栖动物调查,分析其群落结构特征与环境因子的关系.共采集并鉴定出大型底栖动物64个分类单元(种),分属3门6纲32科.结果发现,北京不同区域河流大型底栖动物的密度组成、优势种和物种数存在较大的空间差异,山区是水生昆虫密度最大的区域,平均密度为33.95ind.·m~(-2),主要优势种为蚋科(Simuliidae sp.)、纹石蛾(Hydropsyche sp.)和高山似突摇蚊(Paraciadius alpicola);郊区摇蚊幼虫和寡毛纲的平均密度最大,分别为82.58ind.·m~(-2)和36.21ind.·m~(-2),主要优势种为小云多足摇蚊(Polypedilum nubeculosum)和苍白摇蚊(Chironomus pallidivittatus);市区以腹足纲的密度最大,为88.75ind.·m~(-2),主要优势种为铜锈环棱螺(Bellamya aeruginosa)和梨形环棱螺(Bellamya purificata).市区和郊区发现的物种数均比山区多14种.CCA典范对应分析结果表明,营养盐浓度是影响郊区大型底栖动物群落结构的主要因素,人类活动强度和水温是影响市区和山区大型底栖动物群落结构的主要因素.     

Diversity in the later Paleogene proboscidean radiation: a small barytheriid from the Oligocene of Dhofar Governorate,Sultanate of Oman

Despite significant recent improvements to our understanding of the early evolution of the Order Proboscidea (elephants and their extinct relatives), geographic sampling of the group’s Paleogene fossil record remains strongly biased, with the first ~30 million years of proboscidean evolution documented solely in near-coastal deposits of northern Africa. The considerable morphological disparity that is observable among the late Eocene and early Oligocene proboscideans of northern Africa suggests that other, as yet unsampled, parts of Afro-Arabia might have served as important centers for the early diversification of major proboscidean clades. Here we describe the oldest taxonomically diagnostic remains of a fossil proboscidean from the Arabian Peninsula, a partial mandible of Omanitherium dhofarensis (new genus and species), from near the base of the early Oligocene Shizar Member of the Ashawq Formation, in the Dhofar Governorate of the Sultanate of Oman. The molars and premolars of Omanitherium are morphologically intermediate between those of Arcanotherium and Barytherium from northern Africa, but its specialized lower incisors are unlike those of other known Paleogene proboscideans in being greatly enlarged, high-crowned, conical, and tusk-like. Omanitherium is consistently placed close to late Eocene Barytherium in our phylogenetic analyses, and we place the new genus in the Family Barytheriidae. Some features of Omanitherium, such as tusk-like lower second incisors, the possible loss of the lower central incisors, an enlarged anterior mental foramen, and inferred elongate mandibular symphysis and diminutive P₂, suggest a possible phylogenetic link with Deinotheriidae, an extinct family of proboscideans whose origins have long been mysterious.     

Factors affecting in vitro plant regeneration of the critically endangered Mediterranean knapweed (Centaurea tchihatcheffii Fisch et. Mey)

Habitat destruction has resulted in the extinction of many plant species from the earth, and many more face extinction. Likely, the annual endemic Mediterranean knapweed (Centaurea tchihatcheffii) growing in the Golbasi district of Ankara, Turkey is facing extinction and needs urgent conservation. Plant tissue culture, a potentially useful technique for ex situ multiplication, was used for the restoration of this ill-fated plant through seed germination, micropropagation from stem nodes, and adventitious shoot regeneration from immature zygotic embryos. The seeds were highly dormant and very difficult to germinate. No results were obtained from the micropropagation of stem nodes. However, immature zygotic embryos showed the highest adventitious shoot regeneration on Murashige and Skoog (MS) medium, containing 1 mg l⁻¹ kinetin and 0.25 mg l⁻¹ NAA. Regenerated shoots were best rooted on MS medium containing 1 mg l⁻¹ IBA and transferred to the greenhouse for flowering and seed set. As such, the present work is the first record of in vitro propagation of critically endangered C. tchihatcheffii, using immature zygotic embryos, and is a step forward towards conservation of this indigenous species.     

温榆河水环境质量与浮游植物群落结构的时空变化及其相互关系

温榆河是北京市重要的生态廊道.本研究基于历史文献资料和现场调查,比较分析了2006、2011和2018年温榆河水环境质量与浮游植物群落结构的时空变化,探讨了浮游植物群落变化与水温T、溶解氧DO、pH和营养盐之间的相互关系.结果表明,温榆河水环境质量总体好转,经历了重度污染→污染遏制→水质改善过程,水污染物已从NH_4~+-N为主转向TN为主.NH_4~+-N、TN的平均浓度和平均超标倍数从2011年的15. 52～19. 16 mg·L~(-1)、9. 34～8. 58倍和20. 21～19. 58 mg·L~(-1)、12. 47～8. 79倍降低到2018年的1. 93～2. 66 mg·L~(-1)、0. 29～0. 33倍和5. 66～6. 79 mg·L~(-1)、2. 77～2. 39倍,并且温榆河和支流清河的DO和NH_4~+-N浓度已基本达到水功能区划目标.与水质改善过程相对应,浮游植物群落的物种种类大幅增加,经历了绿藻门(Chlorophyta)→蓝藻门(Cyanophyta)→硅藻门(Bacillariophyta)物种为主的变化过程,Shannon-Wiener多样性指数(H')、均匀度Pielou指数(J)有所改善,但依然存在高耐污绝对优势物种小环藻(Cyclotella)和直链藻(Melosira)等,且2018年温榆河依旧处于中富营养化状态.统计分析结果表明,DO、pH、NH_4~+-N、TN和TP是影响温榆河流域浮游植物多样性和蓝藻、硅藻及其他藻类密度的主要因素.     

Regional,seasonal and interspecific variation in <Superscript>15</Superscript>N and <Superscript>13</Superscript>C in sympatric mouse lemurs

Madagascar provides some of the rare examples where two or more primate species of the same genus and with seemingly identical niche requirements occur in sympatry. If congeneric primate species co-occur in other parts of the world, they differ in size in a way that is consistent with Hutchinson’s rule for coexisting species, or they occupy different ecological niches. In some areas of Madagascar, mouse lemurs do not follow these “rules” and thus seem to violate one of the principles of community ecology. In order to understand the mechanisms that allow coexistence of sympatric congeneric species without obvious niche differentiation, we studied food composition of two identical sized omnivorous mouse lemur species, Microcebus griseorufus and M. murinus with the help of stable isotope analyses (δ ¹⁵N and δ ¹³C). The two species are closely related sister species. During the rich season, when food seems abundant, the two species do not differ in their nitrogen isotope composition, indicating that the two species occupy the same trophic level. But they differ in their δ ¹³C values, indicating that M. griseorufus feeds more on C₄ and CAM (Crassulacean-acid-metabolism) plants than M. murinus. During the lean season, M. murinus has lower δ ¹⁵N values, indicating that the two species feed at different trophic levels during times of food shortage. Hybrids between the two species showed intermediate food composition. The results reflect subtle differences in foraging or metabolic adaptations that are difficult to quantify by traditional observations but that represent possibilities to allow coexistence of species.     

炼油废水对凤眼莲根系微型动物种类、数量和生物量的影响

用凤眼莲净化炼油废水,其根系的生物种类很丰富,成为一个亚生态系统,其中微型动物有20种,轮虫3种,线虫、枝角类等4种.优势种群为沟钟虫、转轮虫和盘状鞍甲轮虫,它们各占总量的18.5％、17.5％和34.5％.炼油废水在氧化塘中滞留期越长,根系微型动物种类和数量越多.从废水的进口到出口凤眼莲根系微型动物总的数最呈增加趋势,最高数量为1.91×10~7个/m~2.对照塘除具有自氧作用的裸藻外,水体中几乎无微型动物.废水滞留期的延长对进、出口凤眼莲根系上好氧和兼性好氧微生物数量的影响不大.     

三峡库区支流澎溪河水华高发期环境因子和浮游藻类的时空特征及其关系

分别在2014年春季和夏季三峡库区水华高发期,在库区北岸最大支流澎溪河流域从其河口处逆流而上至回水末端共布置8个采样点,对浮游藻类和环境因子进行了监测,运用数理统计分析手段,对浮游藻类的群落结构及其与环境因子的关系进行了分析.结果表明在4月中旬,除河口样点外,其他采样点水体出现分层,但断面多只有温跃层和滞温层,而没有混合层;上游水体层次间温差高于下游水体;各采样点的水深以及表层水体(水面向下至0.5 m深的水层)的水温、浊度、p H、电导率、溶解氧、叶绿素a、总氮和总磷的空间分布差异显著(ANOVA,P0.05);共检测到浮游藻类25种(属),丰度在(2.76~145.8)×10~4cell·L~(-1)之间,以角甲藻(Ceratium hirundinella)为主要优势藻,鱼腥藻(Anabaena sp.)为次优势藻;上游接近支流来水的样点S7(63.4×10~4cell·L~(-1))和S8(145.8×10~4cell·L~(-1))水华最为严重;硝酸盐氮、水温、p H、电导率和溶解氧是藻类生长的决定因子.在7月下旬,水体分层,趋势与春季相似;各采样点深度和0~0.5 m水层的水温、浊度、氧化还原电位、p H、电导率、叶绿素a、氨氮、硝酸盐氮、总氮和总磷的空间分布仍然差异显著(ANOVA,P0.05);共检测到浮游藻类46种(属),丰度在(9.56~278.88)×10~4cell·L~(-1)之间,总体以席藻(Phormidium sp.)为主要优势藻,鱼腥藻(Anabaena sp.)为次优势藻;下游接近澎溪河河口的样点S2(216.44×10~4cell·L~(-1))、S3(278.88×10~4cell·L~(-1))和S4(108.12×10~4cell·L~(-1))水华严重;浊度、水深、总氮、氧化还原电位、电导率和溶解氧是藻类生长的决定因子.水体分层与水华形成有重要关系.     

太湖不同湖区轮虫群落结构季节变化的比较研究

2006年7月～2007年6月对太湖不同湖区(河口区、梅梁湾、太湖湖心区和贡湖湾)轮虫的季节变化进行了比较研究.整个研究期间,河口区、梅梁湾、太湖湖心区和贡湖湾轮虫种类数分别为23、15、14和21;河口区轮虫的年平均密度最高,为475个·L-1,梅梁湾最低,为164个·L-1,太湖湖心区为189个·L1-,贡湖湾为338个·L-1.4个湖区优势种不同,河口区轮虫优势种为萼花臂尾轮虫(B.cdyciflorus),梅梁湾为角突臂尾轮虫(B.angularis),太湖湖心区和贡湖湾优势种都是针簇多肢轮虫(P.trigla).食物的不同以及大型浮游甲壳动物的抑制作用,可能是太湖4个湖区轮虫群落结构不同的重要原因.相关分析表明,轮虫数量与枝角类数量、枝角类生物量和桡足类生物量极显著负相关;轮虫数量与透明度显著正相关.结果表明,太湖4个不同湖区轮虫群落结构不同.     

Climate change and the geography of weed damage: Analysis of U.S. maize systems suggests the potential for significant range transformations

By the end of the century, climate change projections under a “business-as-usual” emissions scenario suggest a globally averaged warming of 2.4–6.4 °C. If these forecasts are realized, cropping systems are likely to experience significant geographic range transformations among damaging endemic weed species and new vulnerabilities to exotic weed invasions. To anticipate these changes and to devise management strategies for proactively addressing them, it is necessary to characterize the environmental conditions that make specific weed species abundant, competitive, and therefore damaging the production of particular crops (i.e. defining the damage niche). In this study, U.S. maize is used as a model system to explore the implications of climate change on the distribution of damaging agricultural weeds. To accomplish this, we couple ensemble climate change projections of annual temperature and precipitation with survey data of troublesome weed species in maize. At the state scale, space-for-time substitution techniques are used to suggest the potential magnitude of change among damaging weed communities. To explore how the geography of damage for specific species may evolve over the next century, bioclimatic range rules were derived for two weed species that are pervasive in the Northern (Abutilon theophrasti Medicus, ABUTH) and Southern (Sorghum halepense (L.) Pers., SORHA) U.S. Results from both analyses suggest that the composition of damaging weed communities may be fundamentally altered by climate change. In some states, potential changes in the coming decades are commensurate to those possible by the end of the century. Regions such as the Northeastern U.S. may prove particularly vulnerable with emerging climate conditions favoring few weed species of present-day significance. In contrast, regions like the mid-South are likely to experience fewer shifts even with a similar magnitude in climate change. By the end of the century in the U.S. Corn Belt, cold-tolerant species like A. theophrasti may be of minor importance whereas S. halepense, a predominantly Southern U.S. weed species at present, may become common and damaging to maize production with its damage niche advancing 200–600 km north of its present-day distribution.