Wind farms increase land surface temperature and reduce vegetation productivity in the Inner Mongolia

Wind power has been developing rapidly as a key measure to mitigate human-driven global warming.The under-standing of the development and impacts of wind farms on local climate and vegetation is of great importance for their rational use but is still limited.In this study,we combined remote sensing and on-site investigations to identify wind farm locations in Inner Mongolia and performed landscape pattern analyses using Fragstats.We explored the impacts of wind farms on land surface temperature(LST)and vegetation net primary productivity(NPP)between 1990 and 2020 by contrasting these metrics in wind farms with those in non-wind farm areas.The results showed that the area of wind farms increased rapidly from 1.2 km2 in 1990 to 10,755 km2 in 2020.Spatially,wind farms are mainly clustered in three aggregation areas in the center.Further,wind farms increased nighttime LST,with a mean value of 0.23℃,but had minor impacts on the daytime LST.Moreover,wind farms caused a decline in NPP,especially over forest areas,with an average reduction of 12.37 GC/m^(2).Given the impact of wind farms on LST and NPP,we suggest that the development of wind farms should fully consider their direct and potential impacts.This study provides scientific guidance on the spatial pattern of future wind farms.

Carboniferous-Permian Stratigraphy and Sedimentary Environment of Southeastern Inner Mongolia,China:Constraints on Final Closure of the Paleo-Asian Ocean

In this paper we discuss the timing of final closure of the Paleo-Asian Ocean based on the field investigations of the Carboniferous-Permian stratigraphic sequences and sedimentary environments in southeastern Inner Mongolia combined with the geology of its neighboring areas. Studies show that during the Carboniferous-Permian in the eastern segment of the Tianshan-Hinggan Orogenic System, there was a giant ENE-NE-trending littoral-neritic to continental sedimentary basin, starting in the west from Ejinqi eastwards through southeastern Inner Mongolia into Jilin and Heilongjiang. The distribution of the Lower Carboniferous in the vast area is sparse. The Late Carboniferous or Permian volcanic-sedimentary rocks always unconformably overlie the Devonian or older units. The Upper Carboniferous-Middle Permian is dominated by llttoral-neritic deposits and the Upper Permian, by continental deposits. The Late Carboniferous-Permian has no trace of subduction-collision orogeny, implying the basin gradually disappeared by shrinking and shallowing. In addition, it is of interest to note that the Ondor Sum and Hegenshan ophiolitic melanges were formed in the pre-Late Silurian and pre-Late Devonian respectively, and the Solonker ophiolitic melange formed in the pre-Late Carboniferous. All the evidence indicates that the eastern segment of the Paleo-Asian Ocean had closed before the Late Carboniferous, and most likely before the latest Devonian （Famennian）.

A New Species of Coniopteris moguqiensis sp. nov. from the Middle Jurassic Wanbao Formation in Eastern Inner Mongolia, China

In recent years, an increasing number of plant fossil leaves and petrified woods have been discovered from the Middle Jurassic Wanbao Formation in Moguqi Town of Inner Mongolia, NE China. Here, we describe a new species of Coniopteris moguqiensis sp. nov. preserved as a fragment with fertile and sterile pinnules. The sterile ultimate pinnules are elongate ovate with sphenopteriod type venation, and fertile pinnules are usually isolated, bipinnate at least with the sorus apical, elliptical, 1 mm in diameter;sporangia are almost globular, 100-150 μm in diameter, and the annulus is vertical. In situ spores are rounded-triangular in polar view, 25-30 μm in diameter with sides straight and slightly convex;trilete, laesurae are thin and slightly straight;the exine surface is usually psilate under the light microscope but finely reticuloid sculptured on the proximal view under a scanning electronic microscope. The fern genus Coniopteris usually suggests a warm and humid environment, which is consistent with the palaeoclimatic conditions of petrified wood and megafossil plants. The new discovery further supplements the floral composition of the Wanbao Formation, providing new material for understanding the evolutionary trend and classification of Coniopteris.

Zircon U-Pb Geochronology and Geochemistry of the Early Cretaceous Volcanic Rocks from the Manitu Formation in the Hongol Area, Northeastern Inner Mongolia

We undertook zircon U-Pb dating and geochemical analyses of volcanic rocks from the Manitu Formation in the Hongol area, northeastern Inner Mongolia, to determine their age, petrogenesis and sources, which are important for understanding the Late Mesozoic tectonic evolution of the Great Xing＇an Range. The volcanic rocks of the Manitu Formation from the Hongol area consist primarily of trachyandesite, based on their chemical compositions. The zircons from two of these trachyandesites are euhedral-subhedral in shape, display clear oscillatory growth zoning and have high Th/U ratios （0.31- 1.15）, indicating a magmatic origin. The results of LA-ICP-MS zircon U-Pb dating indicate that the volcanic rocks from the Manitu Formation in the Hongol area formed during the early Early Cretaceous with ages of 138.9-140.5 Ma. The volcanic rocks are high in alkali （Na2O ＋ K2O = 6.22-8.26 wt%）, potassium （K2O = 2.49-4.58 wt%） and aluminium （Al2O3 = 14.27-15.88 wt%）, whereas they are low in iron （total Fe2O3 = 3.76-6.53 wt%） and titanium （TiO2 = 1.02-1.61 wt%）. These volcanic rocks are obviously enriched in large ion lithophile elements, such as Rb, Ba, Th and U, and light rare earth elements, and are depleted in high field strength elements, such as Nb, Ta and Ti with pronounced negative anomalies. Their Sr-Nd-Pb isotopic compositions show positive εNd（t） （＋0.16%o t0＋1.64%o） and low TDM（t） （694--767 Ma）. The geochemical characteristics of these volcanic rocks suggest that they belong to a shoshonitic series and were likely generated from the partial melting of an enriched lithospheric mantle that was metasomatised by fluids released from a subducted slab during the closure of the Mongol- Okhotsk Ocean. Elemental and isotopic features reveal that fractional crystallization with the removal of ferromagnesian minerals, plagioclase, ilmenite, magnetite and apatite played an important role during the evolution of the magma. These shoshonitic rocks were produced by the partial melting of the enriched lithospheric mantle in an extensional regime, which resulted from the gravitational collapse following the final closure of the Mongoi-Okhotsk Ocean in the Middle-Late Jurassic.

Two New Species of Protocedroxylon Gothan(Pinaceae) from the Middle Jurassic of Eastern Inner Mongolia, NE China

Two new coniferous wood taxa, Protocedroxylon zhangii sp. nov. and P. zhalantunense sp. nov., are described from the Middle Jurassic Wanbao Formation in Zhalantun City, Inner Mongolia, NE China. The new discovery represents the first record of petrified wood in the Wanbao Formation, and contributes to further understanding the floral composition, especially that of the forest, of the Wanbao Formation. Anatomically, the two new species are characterized by having a mixed type of radial pitting and Abietineentüpfelung. In extant conifers, Abietineentüpfelung is considered to be characteristic of the wood of Pinaceae. The new discovery further indicates that the first occurrence of Abietineentüpfelung in conifer-like wood should be earlier than the Kimmeridgian. The palaeolatitudinal distribution pattern of Protocedroxylon indicates that the genus is a palaeobiogeographically consistent group, which was probably restricted to wetter and cooler temperate climates. In combination with distinct growth rings, the occurrence of Protocedroxylon suggests that a cool temperate and seasonal climate might have prevailed during the sedimentation period of the Wanbao Formation in eastern Inner Mongolia, NE China. Such a view is also in agreement with the palaeoclimatic conditions indicated by the plant megafossils of the Wanbao Formation.

Petrogenesis of Early Permian Intrusive Rocks from Southeastern Inner Mongolia, China: Constraints on the Tectonic Framework of the Southeastern Central Asian Orogenic Belt

The late Paleozoic tectonic framework of the southeastern Central Asian Orogenic Belt is key to restricting the accretion orogeny between the Siberia Craton and the North China Craton. To clarify the framework, petrogenesis of early Permian intrusive rocks from southeastern Inner Mongolia was studied. Zircon U-Pb dating for bojite and syenogranite from Ar-Horqin indicate that they were emplaced at 288–285 Ma. Geochemical data reveal that the bojite is highly magnesian and low-K to middle-K calc-alkaline, with E-MORB-type REE and IAB-like trace element patterns. The syenogranite is a middle-K calc-alkaline fractionated A-type granite and shows oceanic-arc-like trace element patterns, with depleted Sr-Nd-Hf isotopes,(~(87)Sr/~(86)Sr)I = 0.7032–0.7042, ε_(Nd)(t) = +4.0 to +6.6 and zircon ε_(Hf)(t) = +11.14 to +14.99. This suggests that the bojite was derived from lithospheric mantle metasomatized by subducted slab melt, while the syenogranite originated from very juvenile arc-related lower crust. Usng data from coeval magmatic rocks from Linxi-Ar-Horqin, the Ar-Horqin intra-oceanic arc was reconstructed, i.e., initial transition in 290–280 Ma and mature after 278 Ma. Combined with regional geological and geophysical materials in southeastern Inner Mongolia, an early Permian tectonic framework as ‘one narrow ocean basin of the PAO', ‘two continental marginal arcs on its northern and southern' and ‘one intra-oceanic arc in its southern' is proposed.

The Influence of Plant Diversity and Functional Composition on Ecosystem Stability of Four Stipa Communities in the Inner Mongolia Plateau

The main purpose of this study was to examine the effects of plant species diversity and functional composition (the identity of the plant functional groups) on ecosystem stability of Stipa, communities in the Inner Mongolia Plateau. The research work was based on a 12-year study (from 1984 to 1995) of species abundance, diversity, and primary productivity of four Stipa communities, i.e. S. baicalensis Roshev., S. grandis P. Smirn., S, krylovii Roshev., and S. klemenzii Roshev. respectively. The Shnnon-Wiener index was used as a measurement of plant diversity, while functional composition was used to differentiate the functional groups that were included in the communities. The plant species of four Stipa communities were classified into functional groups based on the differences in life forms and ecological groups, which influence their performance in resource requirements, seasonality of growth, tolerance to water stress, and life history. Plant species were classified into five functional groups based on their differences in life form, shrubs and half shrubs, perennial bunch grasses, perennial rhizome grasses, forbs, annuals and biennials. Based on their differences in water requirement these species were classified into four functional groups: xerads, intermediate xerads, intermediate mesophytes, and mesophytes. The results showed: 1) Plant species diversity stabilized ecosystem processes. Shannon-Wiener index were 2.401 4, 2.172 0, 1.624 8, 0.354 3 from S. baicalensis community to S. grandis, S. krylovii and S. klemenzii community, respectively. The dynamics of the aboveground net primary productivity (ANPP) for a 12-year's period showed a reverse pattern, the coefficients of variation of the four communities were 21.94%, 20.63%, 29.21% and 39.72% respectively. 2) The Life form functional group component of diversity was a greater determinant of the ecosystem processes than the species component of diversity. The effects of perennial bunch grasses, perennial rhizome grasses and forbs on community stability were highly significant. 3) The ecological group component of diversity was also a great determinant of the ecosystem processes. The effects of xerads, intermediate xerads, and mesophytes on community stability were also very strong.

Genetic Mechanism of Mineral Inclusions in Zircons from the Khondalite Series, Southeastern Inner Mongolia

The early Precambrian khondalite series is widely distributed in theJining-Zhuozi-Fengzhen-Liangcheng area, southeastern Inner Mongolia. The khondalite series mainlyconsists of sillimanite garnet potash feldspar (or two-feldspar) gneiss and garnet biotiteplagioclase gneiss. These gneissic rocks have commonly experienced granulite-facies metamorphism. Inzircons separated from sillimanite garnet potash feldspar gneisses, many mineral inclusions,including Sil, Grt, Ky, Kfs, Qtz and Ap, have been identified by the Laser Raman spectroscopy.Generally, prograde metamorphic mineral inclusion assemblages such as Ky + Kfs + Qtz + Ap and Ky +Grt + Kfs + Qtz are preserved in the core of zircon, while peak granulite-facies metamorphicminerals including Sil + Grt + Kfs + Qtz and Sil + Gif + Kfs + Qtz + Ap are identified in the mantleand rim of the same zircon. However, in some zircons are only preserved the peak metamorphicminerals such as Sil + Grt + Kfs + Qtz and Sil + Grt + Kfs + Qtz + Ap from core to rim, and inothers are inherited the primary cores with minor mineral inclusions of Kfs + Qtz, with peakmetamorphic mineral inclusions around the inherited cores. These data indicate that the mineralassemblage evolution of sillimanite garnet potash feldspar gneisses in the study are did experiencea polymorphic transformation of kyanite to sillimanite. In garnet biotite plagioclase gneisses,secondary electron microscopic images reveal that most zircons display distinct zoning textures,which comprise cores and rims, each with distinctive inclusion assemblages. The inherited mineralinclusions, mainly consisting of Kfs + Pl + Qtz, Kfs + Qtz and Kfs + Qtz + Ap, are preserved in theprimary cores, while peak granulite-facies mineral asemblages, including Grt + Bt + Pl + Qtz + Ap,Grt + Bt + Pl + Qtz and Grt + Bt + Pl + Qtz + Rt, are identified on the rims. The occurrence of peakmetamorphic mineral inclusions in zircons indicates that these gneissic rocks, includingsillimanite garnet potash feldspar gneiss and garnet biotite plagioclase gneiss, have experiencedgranulite-facies metamorphism. Secondary electron microscopic images of zircons from the khondaliteseries display distinct zoning from core to rim, and are genetically related to the primary,prograde, and peak metamorphic mineral inclusion assemblages respectively. These images revealirregular zoning patterns and varying thickness of cores and rims. The abundance of inclusionscomplicates the conventional U-Pb age dating. Therefore, the SHRIMP micro-spot U-Pb method isessential for the protolith and metamorphic age dating of the khondalite series, southeastern InnerMongolia.

Genetic Analysis on the Lambing Effects of Ewe Inner Mongolia Cashmere Goat

[Objective] The aim of this study was to explore the genetic law of litter size of Inner Mongolia Cashmere Goat.[Method] A total of 22 721 litter records from 3 044 mothers were statistically analyzed.[Result] As shown by the least square variance analysis,the sex,parity and birth type had significant effect on lamb birth weight.As indicated by restricted maximum likelihood method,the parity,population and maternal effect influenced litter size significantly.The birth weight heritability of single lamb,twins and total was 0.16,0.40 and 0.17,respectively.[Conclusion] The study provided a certain basis for the establishment of Inner Mongolia Cashmere Goat line with superior reproductive performance.

Analysis of Heavy Metal Content in Food Crops Planted Along the Shaanxi Inner Mongolia Expressway

To understand the effect of the running of Shaanxi Inner Mongolia Expressway on food crops planted along the sides, we determined the heavy metal contents(Zn, Pb, Cu and Cb) in the digestion solutions of the root, stem and leaf from rice and corn. The results showed that highway promoted the accumulation of heavy metal elements in corn and rice. Compared with the CKs(crops produced where no highway extend), contents of heavy metal elements in two crops tested from two sampling sites were both over standard. This indicates that food crops planted within 100 m away from the highway are been polluted by heavy metals, which is directly related with the running of Shaanxi Inner Mongolia Expressway. Based on this, the areas within 100 m away from the highway are not suggested to cultivate food crops.

Effects of Enclosure on Grassland Ecological and Economic Benefits in Northern China

Grasslands in northern China serve the country as both an ecological barrier and a livestock production base.There,installing enclosures has been becoming the major grassland restoration measure adopted by many local governments.However,the effects of restoration on both ecological and production benefits of grassland remain unclear for implemented grassland restoration policies.Therefore,a representative rangeland in northern China,the Maodeng pasture in Inner Mongolia Autonomous Region was selected as the study area,and remote sensing monitoring analyses were carried out to quantify the ecological benefits and economic benefits from 2015 to 2021.The results showed that:1) in terms of ecological benefits,the grassland area with a grassland coverage rate of more than 60% accounts for 32.3% of the regional area,and 86.4% of its grassland grew significantly better than the same period in2015,showing a significant improvement in grassland growth.Using the average amount of carbon per unit area as the ecological benefit evaluation index,it increased by 27.1% to 32.48Tg C/yr from 2015 to 2021.2) In terms of economic benefits,both theoretical grass production and livestock carrying capacity increased from 2015 to 2021.Compared to 2015,the theoretical grass production in 2021 increased by 24.8% to 71 900 t.The livestock carrying capacity reached 52 100 sheep units in 2021,nearly 11 000 sheep units more than that in 2015.During the study period,multiple economic indicators(on a per capita basis of permanent residents) for the pastoral area of Xilinhot City to which the Maodeng pasture belongs,have grown steadily.Per capita total income rose from 29 630 yuan(RMB) in2015 to 62 859 yuan(RMB) in 2021.Relying on grassland resources to develop the pastoral ecology also broadens the potential economic development space.Overall,the establishment of the reserve and the experiment of implanting an enclosure policy have had a significant and positive impact on Maodeng pasture’s development from both an ecological and economic perspective.With the support of scientific evidence,enclosure policy can be extended to more than 110 000 km~2 of grasslands in northern China with similar precipitation and temperature conditions,enhancing the productive and ecological potential of grasslands.The above research results will contribute to the scientific formulation of grassland pasture quality improvement plans in northern China.

Assessment of land degradation in Inner Mongolia between 2000 and 2020 based on remote sensing data

Achieving land degradation neutrality(LDN)worldwide is a significant target of the Sustainable Development Goal(SDG15.3).Inner Mongolia,as a typical dryland region in northern China,has carried out several large-scale ecological restoration programs to combat land degradation.However,there is a lack of comprehensive assess-ment of its land degradation situation after ecological programs implementation,which is of great significance to supporting SDG15.3 in China.This study analyzed the land degradation situation using the improved SDG15.3.1 calculation framework based on fine resolution data in Inner Mongolia from 2000 to 2020,and finally compre-hensively evaluated the land status of the whole region and those subject to ecological programs.The results show that net land restoration proportion of various ecological project regions and whole region continues to increase.The scope of the Grain for Green Program(GGP)had the largest proportion of net land restoration while the Natural Reserve Program(NRP)had the lowest proportion from 2000 to 2020.The net land restoration area of Inner Mongolia during 2000-2010 and 2010-2020 was 35,800 km 2 and 65,300 km 2,respectively.Overall,Inner Mongolia has achieved statistically zero growth in land degradation under the governance of ecological restora-tion programs.Therefore,reasonable planning,well monitoring,and timely assessment of ecological restoration programs are crucial to support SDG15.3.

New ratite eggshell material from the Miocene of Inner Mongolia,China

Some Miocene ratite eggshell fragments from Gashunyinadege (about 17.5 Ma) and Baogedawula (7.11 ± 0.48 Ma), Inner Mongolia, China, are described. The outer surfaces of eggshell fragments from Gashunyinadege are smooth with a sting pore pattern, while their entire thickness is around 2.12 mm. In a cross-sectional view, the surface crystal layer is very thin and the ratio of cone layer to the those from Gashunyinadege, but seem much thinner and have a lower pore density. Both characteristics fit aepyornithid-type eggshells, implying that the distribution of aepyornithid-type eggshells can be extended to East Asia. The sediments at Gashunyinadege date to approximately 17.5 Ma, implying that the specimens from this locality are relatively early examples of aepyornithid-type eggshells. Aepyornithidtype eggshells seem to have appeared in Eurasia much earlier than struthionid-type eggshells. The faunal compositions in the two localities reflect gradual drying of the Mongolian plateau during the Miocene. A reduction in the number of pores 10 Ma ago, probably occurred in response to this drying process.

Preview of the No.1148 Ramsar Site on the Ordos upland of western Inner Mongolia

The Taolimiao-Alashan Nur (T-A Nur), of about 10 km2 a brackish lake located on the Ordos upland of western Inner Mongolia, northern China, used to

Enhanced soil moisture improves vegetation growth in an arid grassland of Inner Mongolia Autonomous Region, China

Climate change impacts on grasslands that cover a quarter of the global land area, have become unprecedented during the 21~(st) century. One of the important ecological realms, arid grasslands of northern China, which occupy more than 70% of the region's land area. However, the impact of climate change on vegetation growth in these arid grasslands is not consistent and lacks corresponding quantitative research. In this study, NDVI(normalized difference vegetation index) and climate factors including temperature, precipitation, solar radiation, soil moisture, and meteorological drought were analyzed to explore the determinants of changes in grassland greenness in Inner Mongolia Autonomous Region(northern China) during 1982–2016. The results showed that grasslands in Inner Mongolia witnessed an obvious trend of seasonal greening during the study period. Two prominent climatic factors,precipitation and soil moisture accounted for approximately 33% and 27% of grassland NDVI trends in the region based on multiple linear regression and boosted regression tree methods. This finding highlights the impact of water constraints to vegetation growth in Inner Mongolia's grasslands. The dominant role of precipitation in regulating grassland NDVI trends in Inner Mongolia significantly weakened from 1982 to 1996, and the role of soil moisture strengthened after 1996. Our findings emphasize the enhanced importance of soil moisture in driving vegetation growth in arid grasslands of Inner Mongolia, which should be thoroughly investigated in the future.

Responses of vegetation yield to precipitation and reference evapotranspiration in a desert steppe in Inner Mongolia,China

Drought,which restricts the sustainable development of agriculture,ecological health,and social economy,is affected by a variety of factors.It is widely accepted that a single variable cannot fully reflect the characteristics of drought events.Studying precipitation,reference evapotranspiration(ET_(0)),and vegetation yield can derive information to help conserve water resources in grassland ecosystems in arid and semi-arid regions.In this study,the interactions of precipitation,ET_(0),and vegetation yield in Darhan Muminggan Joint Banner(DMJB),a desert steppe in Inner Mongolia Autonomous Region,China were explored using two-dimensional(2D)and three-dimensional(3D)joint distribution models.Three types of Copula functions were applied to quantitatively analyze the joint distribution probability of different combinations of precipitation,ET_(0),and vegetation yield.For the precipitation–ET_(0)dry–wet type,the 2D joint distribution probability with precipitation≤245.69 mm/a or ET_(0)≥959.20 mm/a in DMJB was approximately 0.60,while the joint distribution probability with precipitation≤245.69 mm/a and ET_(0)≥959.20 mm/a was approximately 0.20.Correspondingly,the joint return period that at least one of the two events(precipitation was dry or ET_(0)was wet)occurred was 2 a,and the co-occurrence return period that both events(precipitation was dry and ET_(0)was wet)occurred was 5 a.Under this condition,the interval between dry and wet events would be short,the water supply and demand were unbalanced,and the water demand of vegetation would not be met.In addition,when precipitation remained stable and ET_(0)increased,the 3D joint distribution probability that vegetation yield would decrease due to water shortage in the precipitation–ET_(0)dry–wet years could reach up to 0.60–0.70.In future work,irrigation activities and water allocation criteria need to be implemented to increase vegetation yield and the safety of water resources in the desert steppe of Inner Mongolia.

Spatial changes and driving factors of lake water quality in Inner Mongolia, China

Lakes play important roles in sustaining the ecosystem and economic development in Inner Mongolia Autonomous Region of China,but the spatial patterns and driving mechanisms of water quality in lakes so far remain unclear.This study aimed to identify the spatial changes in water quality and the driving factors of seven lakes(Juyanhai Lake,Ulansuhai Lake,Hongjiannao Lake,Daihai Lake,Chagannaoer Lake,Hulun Lake,and Wulannuoer Lake)across the longitudinal axis(from the west to the east)of Inner Mongolia.Large-scale research was conducted using the comprehensive trophic level index(TLI(Σ)),multivariate statistics,and spatial analysis methods.The results showed that most lakes in Inner Mongolia were weakly alkaline.Total dissolved solids and salinity of lake water showed obvious zonation characteristics.Nitrogen and phosphorus were identified as the main pollutants in lakes,with high average concentrations of total nitrogen and total phosphorus being of 4.05 and 0.21 mg/L,respectively.The values of TLI(Σ)ranged from 49.14 to 71.77,indicating varying degrees of lake eutrophication,and phosphorus was the main driver of lake eutrophication.The lakes of Inner Mongolia could be categorized into lakes to the west of Daihai Lake and lakes to the east of Daihai Lake in terms of salinity and TLI(Σ).The salinity levels of lakes to the west of Daihai Lake exceeded those of lakes to the east of Daihai Lake,whereas the opposite trend was observed for lake trophic level.The intensity and mode of anthropogenic activities were the driving factors of the spatial patterns of lake water quality.It is recommended to control the impact of anthropogenic activities on the water quality of lakes in Inner Mongolia to improve lake ecological environment.These findings provide a more thorough understanding of the driving mechanism of the spatial patterns of water quality in lakes of Inner Mongolia,which can be used to develop strategies for lake ecosystem protection and water resources management in this region.

Radiometric Dating of Ignimbrite from Inner Mongolia Provides no Indication of a Post-Middle Jurassic Age for the Daohugou Beds

Lacustrine deposits exposed at Daohugou, Inner Mongolia, China, have yielded superbly preserved vertebrate fossils. The fossil beds were first misinterpreted as of Early Cretaceous age, based on alleged occurrences of key fossils of the Jehol Biota. Compelling evidence revealed by more rigorous research involving regional biostratigraphy, radiometric dating, and paleontology supports the Middle Jurassic age of the fossil beds. Despite the awesome evidence for the Middle Jurassic age of the Daohugou beds, the age dispute has been resurrected recently by invoking an overturned stratigraphic sequence. A careful review of the data, however, found no evidence that this sequence has been overturned. In addition, many of the assumptions, on which the conjecture of the fossil beds being post- Middle Jurassic is imprudently based, are self-contradictory or otherwise misleading. Thus, the post- Middle Jurassic age of the Daohugou beds as an unfounded conclusion can readily be dismissed.

A New Species of Cathayornis from the Lower Cretaceous of Inner Mongolia,China and Its Stratigraphic Significance

An incomplete postcranial avian skeleton is described from the Lower Cretaceous Jingchuan Formation of Otog Banner of western Inner Mongolia and referred to a new species of Cathayornis, C. chabuensis sp. nov. This is the first report of a Cathayornis from outside Liaoning Province. The new discovery indicates that Cathayornis coexisted with Otogornis genghisi, and a more detailed comparison between these two enantiornithine genera shows that Otogornis represents a more primitive genus than Cathayornis. Our analyses further indicate that Cathayornis is an arboreal bird. The discovery of a Cathayornis from this region also confirms that the avian fossil-bearing Jingchuan Formation is comparable to the Jiufotang Formation of the upper Jehol Group in western Liaoning, and should be referred to the middle-late Early Cretaceous.