河南淅川盆地的恐龙蛋

记述了河南淅川盆地10个地点发现的恐龙蛋化石计6种,分属于4个科6个属．其中新属1个、新种2个。新属、新种滔河扁圆蛋（Placoolithustaohensis）以其特有的壳单元分枝特征成为树枝蛋科的新型分子;另一新种渐川树枝蛋（Dendroolithusxichuanensis）与湖北安陆王店树枝蛋（D．wandianensis）性质相似,两者时代应彼此相当;含滔河扁圆蛋的马家村组下部应与其下含淅川树枝蛋的高沟组划归同一时段为宜,即晚白垩世早期;含副圆形蛋、椭圆形蛋、长形蛋、南雄蛋的马家村组中、上部和其上的寺沟组,时代应属晚白垩世中、晚期。     

Shell Beds as paleoecological puzzles: A case study from the Upper Permian of the Paraná Basin, Brazil

Summary Microstratigraphic, sedimentological, and taphonomic features of the Ferraz Shell Bed, from the Upper Permian (Kazanian-Tatarian?) Corumbataí Formation of Rio Claro Region (the Paraná Basin, Brazil), indicate that the bed consists of four distinct microstratigraphic units. They include, from bottom to top, a lag concentration (Unit 1), a partly reworked storm deposit (Unit 2), a rapidly deposited sandstone unit with three thin horizons recording episodes of reworking (Unit 3), and a shell-rich horizon generated by reworking/winnowing that was subsequently buried by storm-induced obrution deposit (Unit 4). The bioclasts of the Ferraz Shell Bed represent exclusively bivalve mollusks.Pinzonellaillusa andTerraia aequilateralis are the dominant species. Taphonomic analysis indicates that mollusks are heavily time-averaged (except for some parts of Unit 3). Moreover, different species are time-averaged to a different degree (disharmonious time-averaging). The units differ statistically from one another in their taxonomic and ecological composition, in their taphonomic pattern, and in the size-frequency distributions of the two most common species. Other Permian shell beds of the Paraná Basin are simílar to the Ferraz Shell Bed in their faunal composition (they typically contain similar sets of 5 to 10 bivalve species) and in their taphonomic, sedimentologic, and microstratigraphic characteristics. However, rare shell beds that include 2–3 species only and are dominated by articulated shells preserved in life position also occur. Diversity levels in the Permian benthic associations of the Paraná Basin were very low, with the point diversity of 2–3 species and with the within-habitat and basin-wide (alpha and gamma) diversities of 10 species, at most. The Paraná Basin benthic communities may have thus been analogous to low-diversity bivalve-dominated associations of the present-day Baltic Sea. The ‘Ferraz-type’ shell beds of the Paraná Basin represent genetically complex and highly heterogeneous sources of paleontological data. They are cumulative records of spectra of benthic ecosystems time-averaged over long periods of time (10²–10⁴ years judging from actualistic research). Detailed biostratinomic reconstructions of shell beds can not only offer useful insights into their depositional histories, but may also allow paleoecologists to optimize their sampling designs, and consequently, refine paleoecological and paleoenvironmental interpretations.     

Effects of European colonization on indigenous ecosystems: post-settlement changes in tree stand structures in Eucalyptus–Callitris woodlands in central New South Wales, Australia

Aim There has been considerable debate about pre‐settlement stand structures in temperate woodlands in south‐eastern Australia. Traditional histories assumed massive tree losses across the region, whereas a number of recent histories propose that woodlands were originally open and trees regenerated densely after settlement. To reconcile these conflicting models, we gathered quantitative data on pre‐settlement stand structures in Eucalyptus–Callitris woodlands in central New South Wales Australia, including: (1) tree density, composition, basal area and canopy cover at the time of European settlement; and (2) post‐settlement changes in these attributes. Location Woodlands dominated by Eucalyptus species and Callitris glaucophylla, which originally occupied approximately 100,000 km² in central New South Wales, Australia. Methods We recorded all evidence of pre‐settlement trees, including stumps, stags and veteran trees, from 39 relatively undisturbed 1‐ha stands within 16 State Forests evenly distributed across the region. Current trees were recorded in a nested 900 m² quadrat at each site. Allometric relationships were used to estimate girth over bark at breast height, tree basal area, and crown diameter from the girth of cut stumps. A post‐settlement disturbance index was developed to assess correlations between post‐settlement disturbance and attributes of pre‐settlement stands. Results The densities of all large trees (> 60 cm girth over bark at breast height) were significantly greater in current stands than at the time of European settlement (198 vs. 39 trees ha^?1). Pre‐settlement and current stands did not differ in basal area. However, the proportional representation of Eucalyptus and Callitris changed completely. At the time of settlement, stands were dominated by Eucalyptus (78% of basal area), whereas current stands are dominated by Callitris (74%). On average, Eucalyptus afforded 83% of crown cover at the time of settlement. Moreover, the estimated density, basal area and crown cover of Eucalyptus at the time of settlement were significantly negatively correlated with post‐settlement disturbance, which suggests that these results underestimate pre‐settlement Eucalyptus representation in the most disturbed stands. Main conclusions These results incorporate elements of traditional and recent vegetation histories. Since European settlement, State Forests have been transformed from Eucalyptus to Callitris dominance as a result of the widespread clearance of pre‐settlement Eucalyptus and dense post‐settlement recruitment of Callitris. Tree densities did increase greatly after European settlement, but most stands were much denser at the time of settlement than recent histories suggest. The original degree of dominance by Eucalyptus was unexpected, and has been consistently underestimated in the past. This study has greatly refined our understanding of post‐settlement changes in woodland stand structures, and will strengthen the foundation for management policies that incorporate historical benchmarks of landscape vegetation changes.     

Phylogeographical structure in the coastal species Senecio rodriguezii (Asteraceae), a narrowly distributed endemic Mediterranean plant

Aim Our goals were (1) to assess the levels of chloroplast DNA variation in a narrowly distributed plant restricted to continental islands, (2) to ascertain whether a phylogeographical structure is present in plants restricted to coastal linear systems, and (3) to interpret the results in the light of the known palaeogeography of these islands. Location The Eastern Balearic Islands (Majorca and Minorca) in the Western Mediterranean Basin. Methods Sampling included 134 individuals from 28 populations of Senecio rodriguezii covering the entire range of the species. Sequences of the chloroplast genome (trnT–trnL spacer) were obtained and parameters of population genetic diversity and substructure were determined (h_sh_t, G_st). The geographical structure of genetic variation was assessed by an analysis of molecular variance (AMOVA). Additionally, a spatial AMOVA (SAMOVA) was used to identify groups of populations that were geographically homogeneous and maximally differentiated from each other. Finally, a pattern of isolation by distance was assessed by testing the correlation between the matrix of pairwise Φ_ST values and the matrix of geographical distances between pairs of populations using a Mantel test. Results Seven haplotypes were detected in S. rodriguezii. Only two of them were shared between islands; all of the others were restricted to Majorca (two) or Minorca (three). Overall, we found high levels of genetic diversity and significant geographical structuring of cpDNA markers. Most of the variation detected can be attributed to differences among populations (84.6%), but there was also a significant differentiation between the islands. Main conclusions Our results support the view that the Balearic Islands constitute a reservoir of genetic diversity, not only for widespread Mediterranean taxa, but also for endemic ones. The intraspecific genetic structure found in S. rodriguezii suggests that its population history was dominated by both expansion and contraction events. This has resulted in a species that is highly structured genetically, showing very few shared haplotypes between islands, and a high number of haplotypes restricted to small geographical areas within the islands. Changes in habitat availability and dynamic processes of population fragmentation and connectivity due to repeated cycles of sea‐level changes during the Quaternary are the possible underlying factors that have shaped the cpDNA pool of this endemic species on a regional scale.     

Effects of changing climate on aquatic habitat and connectivity for remnant populations of a wide‐ranging frog species in an arid landscape

Amphibian species persisting in isolated streams and wetlands in desert environments can be susceptible to low connectivity, genetic isolation, and climate changes. We evaluated the past (1900–1930), recent (1981–2010), and future (2071–2100) climate suitability of the arid Great Basin (USA) for the Columbia spotted frog (Rana luteiventris) and assessed whether changes in surface water may affect connectivity for remaining populations. We developed a predictive model of current climate suitability and used it to predict the historic and future distribution of suitable climates. We then modeled changes in surface water availability at each time period. Finally, we quantified connectivity among existing populations on the basis of hydrology and correlated it with interpopulation genetic distance. We found that the area of the Great Basin with suitable climate conditions has declined by approximately 49% over the last century and will likely continue to decline under future climate scenarios. Climate conditions at currently occupied locations have been relatively stable over the last century, which may explain persistence at these sites. However, future climates at these currently occupied locations are predicted to become warmer throughout the year and drier during the frog's activity period (May – September). Fall and winter precipitation may increase, but as rain instead of snow. Earlier runoff and lower summer base flows may reduce connectivity between neighboring populations, which is already limited. Many of these changes could have negative effects on remaining populations over the next 50–80 years, but milder winters, longer growing seasons, and wetter falls might positively affect survival and dispersal. Collectively, however, seasonal shifts in temperature, precipitation, and stream flow patterns could reduce habitat suitability and connectivity for frogs and possibly other aquatic species inhabiting streams in this arid region.     

Gigantism among Late Jurassic limulids: New ichnological evidence from the Causses Basin (Lozère,France) and comments on body-size evolution among horseshoe crabs

An abundant ichnological material composed of xiphosuran trackways and isolated traces was discovered in Upper Jurassic limestones from the Causses Basin (Causse Méjean, Lozère, France). The morphology of the imprints supports their identification as Kouphichnium isp. In contrast to the most frequent case, the trackways are composed of omnipresent pusher imprints sometime associated with leg traces, but with no telson mark. We argue that this pattern reflects actual surface traces rather than an incomplete set of undertracks. The size distribution of the sampled ichnites is broadly bimodal. This is best explained by sexual dimorphism, a phenomenon frequently observed in modern xiphosurans. Analysis of the trace fossils further suggests that several growth stages are recorded and that the horseshoe crabs were walking in a protected and flat environment like a lagoon. This area, certainly close to a mating ground, was occasionally affected by a continental influence. The biometric study of the tracks suggests a gigantic size for the trackmakers whose body may have reached 84 cm in length. This discovery complements the few reports on other gigantic horseshoe crabs in the Jurassic of Western Europe, thus casting doubt on the postulated increase in body size from the Palaeozoic to the Recent. Furthermore, a literature review shows that there are still major gaps in the record of limulid body-fossils and tracks. Thus, neither of these archives can be taken at face value for quantifying the body-size evolution of horseshoe crabs.     

Lower Carboniferous (middle Visean) foraminifers and algae from an interior sea,Southern Carnarvon Basin,Australia

A moderate diversity biota of foraminifers, algae and calcareous microproblematica is recorded from the Lower Carboniferous Yindagindy Formation within the intracratonic Southern Carnarvon Basin in Western Australia. Very shallow metahaline to hypersaline conditions are suggested. The palaeobotanical components are sporadic calcitarcha, tuberitinaceans, codiaceans Orthriosiphon? sp. 1, dasycladaleans? Koninckopora tenuiramosa, and algosponges Issinella devonica, Serrisinella cf. serrensis, Issinella? sp. 1, Kamaena cf. awirsi, Proninella? sp. and Stacheoides spp. The foraminiferal assemblage is dominated by a new koktjubinid taxon: Praekoktjubina yindagindyensis nov. gen., nov. sp. Subordinate associated foraminifers are more sporadic Salpingothurammina? sp. 1, Plectinopsis michelseni nov. gen., nov. sp., Rectopravina multifida nov. gen., nov. sp. (with 4 morphotypes), and scarce Endothyra spp. Despite many of these taxa being endemic, a middle Visean age is probable, based on: (1) the maximum global geographic extent of K. tenuiramosa reached during the middle Visean, (2) the disappearance of Plectinopsis nov. gen. in Palaeotethys and the Urals, and (3) the first occurrence of Praekoktjubina nov. gen. in Palaeotethys. An age no older than the middle Visean is supported by sparse conodonts from the Formation and comparison to episodes of carbonate deposition in the Bonaparte Basin, further north in the East Gondwana rift system. Absence of middle Visean archaediscoids may be due to high salinity. The following algal and foraminiferal families and superfamilies are emended: Scribroporellaceae (a lectotype is selected for Orthriosiphon saskatchewanense); Palaeospiroplectamminidae (due to the creation of Plectinopsis nov. gen.); Haplophragminoidea (due to the creation of Rectopravina nov. gen.); and Globivalvulinoidea and Koktjubinidae (due to the creation of Praekoktjubina nov. gen.).     

浙江天台晚白垩世巨型长形蛋科一新属及巨型长形蛋科的分类订正

浙江天台盆地上白垩统赤城山组发现的巨型长形蛋类可鉴定为西峡巨型长形蛋(Macroelongatoolithusxi xiaensis)和一新蛋属、新蛋种——桥下巨型纺锤蛋(Megafusoolithus qiaoxiaensis oogen.etoosp.nov.)。西峡巨型长形蛋此前仅发现于河南西峡盆地,其特征为个体巨大(35cm),蛋壳外表面具瘤点状纹饰,蛋壳锥体层与柱状层界线明显,呈波浪形,锥体层与柱状层厚度之比为1:5—1:2。已记述的产自天台的张氏巨型长形蛋(M.zhangi)和产自河南西峡盆地的西峡长圆柱蛋(Longiteresoolithus xixiaensis)均为西峡巨型长形蛋的同物异名。桥下巨型纺锤蛋的特征包括蛋壳中部外表面具有棱脊状纹饰,蛋壳锥体层与柱状层界线不明显,二者厚度之比近1:3,这些特征区别于巨型长形蛋属。目前已知巨型长形蛋科仅包含巨型长形蛋属和巨型纺锤蛋属,订正的科征为:蛋化石巨大,长径大于35cm;蛋长形,两端大致对称,长宽之比约为3:1;蛋化石在蛋窝中一般两枚为一组,呈单层圆环状排列,蛋窝直径近3m;蛋壳外表面具瘤点状或棱脊状纹饰,蛋壳由锥体层与柱状层组成。这些特征明显区别于其他类型的蛋化石,因此它们代表了一个独立的蛋科:巨型长形蛋科(Macroelongatoolithidae)。     

A new species of Pliopithecus Gervais, 1849 (Primates: Pliopithecidae) from the Middle Miocene (MN8) of Abocador de Can Mata (els Hostalets de Pierola,Catalonia, Spain)

Pliopithecus (Pliopithecus) canmatensis sp. nov. is described from several Late Aragonian localities from Abocador de Can Mata (ACM) in els Hostalets de Pierola (Vallès‐Penedès Basin, Catalonia, Spain), spanning from ～11.7 to 11.6 Ma (C5r.3r subchron), and being correlated to the MN8 (reference locality La Grive L3). The ACM remains display a pliopithecine dental morphology with well‐developed pliopithecine triangles on M/2 and M/3. This, together with other occlusal details, negates an attribution to the subgenus Epipliopithecus. Although slightly smaller, the ACM remains are most similar in size to comparable elements of P. piveteaui and P. antiquus. Several occlusal details (such as the greater development of the buccal cingulid in lower molars) and dental proportions (M/3 much longer than M/2), however, indicate greater similarities with P. antiquus from Sansan and La Grive. The ACM remains, however, differ from P. antiquus in dental proportions as well as occlusal morphology of the lower molars (including the less peripheral position of the protoconid and more medial position of the hypoconulid, the more mesial position of the buccal cuspids as compared to the lingual ones, the narrower but distinct mesial fovea, the higher trigonid, and the more extensive buccal cingulid, among others). These differences justify a taxonomic distinction at the species level of the ACM pliopithecid remains with respect to P. antiquus. Previous pliopithecid findings from the Vallès‐Penedès Basin, previously attributed to P. antiquus, are neither attributable to the latter species nor to the newly erected one. Am J Phys Anthropol, 2010. © 2009 Wiley‐Liss, Inc.     

Community Structure of Wetland Birds During Spring Migration Through the Rainwater Basin

Abstract: Staging areas and migratory stopovers of wetland birds have the potential to function as geographic bottlenecks; entire populations within a flyway may be affected by the quality and quantity of available wetland habitat at stopover sites. Although approximately 90% of playa wetlands in the Rainwater Basin (RWB) region of south-central Nebraska, USA, have been destroyed, the area still provides essential stopover habitat for >10 million waterfowl each spring. We evaluated community patterns and species associations to assess importance of assembly rules in structuring wetland bird communities during migration and to better facilitate multispecies conservation and management strategies. We surveyed 36–40 playas twice weekly in the RWB and observed approximately 2.6 million individual migratory wetland birds representing 72 species during 3 spring migrations 2002–2004. We evaluated spatial and temporal species co-occurrence patterns of geese, dabbling ducks, diving ducks, and shorebirds using null model analysis. Goose species co-occurrence scores did not differ from random in any year of the study, suggesting that goose species frequently use the same habitats during migration. Co-occurrence patterns among dabbling ducks were not different than expected by chance in any year; however, when we evaluated co-occurrence at a weekly scale, dabbling ducks co-occurred less often than expected during weeks of peak migration (high abundance), indicating that dabbling duck species spatially segregated at high densities. Diving duck co-occurrence patterns did not differ from random in any year, suggesting that diving duck species used the same habitats during migration. Shorebird species co-occurred less often than expected in 2002 and 2004, and during weeks of high shorebird abundance, indicating that shorebird communities were distinctly structured during those times. Most association values among lesser snow geese (Chen caerulescens) and dabbling duck species were positive, indicating dabbling ducks did not avoid wetlands with snow geese, a concern for waterfowl managers. However, we frequently observed snow geese and dabbling ducks using different microhabitats within a wetland, which indicate species associations and co-occurrence patterns may have occurred at a finer spatial scale than we measured. This approach of co-occurrence analysis will allow wildlife managers charged with multispecies management at migration stopover sites to make informed conservation and management decisions based on community structure rather than historic single-species approaches.