Wang et al. (Research Articles, 3 June 2022, eabl8316) reported an early Miocene giraffoid that exhibited fierce head-butting behavior and concluded that sexual selection promoted head-neck evolution in giraffoids. However, we argue that this ruminant is not a giraffoid and thus that the hypothesis that sexual selection promoted giraffoid head-neck evolution is not sufficiently supported.

Insectivoran mammals have been recovered by Sino-American field teams from various localities in each formation of the Yuncu and TancunTancun (village) subbasins. They were an important component of late Miocene through Pliocene faunas of North China. One hedgehogHedgehog has been found in late Pliocene and Pleistocene localities. Moles, however, are diverse and occur throughout the Miocene and Pliocene section, with one early Pliocene record of the water mole Desmana . The Yushe collection includes the Pliocene talpine Scaptochirus Scaptochirus , which is at present the oldest fossil of this genus. Shrews are also diverse, including multiple representatives of the tribes Soricini, Nectogalini, and Beremendiini. Presence of a blarinine suggests immigration of this element from North America by 6 Ma, and morphological similarity with beremendiines suggests that recognition of these groups should be reviewed. The early Pleistocene Haiyan Formation has yielded only Sorex, and to date only Crocidura Crocidura has emerged from the Pleistocene loessLoess . Declining insectivoran diversity corresponds with a hypothetical decline in mean annual temperature. The insectivoran component of Yushe shows affinity with fossil and living faunas of North China, and a majority of elements are shared broadly across Eurasia. Two taxa at least ( Yunoscaptor Yunoscaptor and Soriculus) also occur in South China, indicating former wide distribution of these genera, and suggesting southward retraction of their preferred paleohabitat from Shanxi Province since the Pliocene.

Despite the wealth of small mammals in the Late Neogene of Yushe Basin, gerbils are not an abundant or diverse element. A single genus, Pseudomeriones Schaub, 1934, is known in the Miocene-Pliocene deposits of Yushe, although the Pleistocene introduces a new fauna containing Meriones Illiger, 1811. The well-known species Pseudomeriones abbreviatus (Teilhard de Chardin, 1926) is recorded in the Pliocene deposits of ZhangcunZhangcun subbasin, south of Yushe. Whereas this species remains undocumented for Yuncu subbasin, Miocene age sediments have produced a lower crowned member of the genus, P. latidens Sen, 2001. We describe these remains and summarize their stratigraphic occurrence. The low crowned Miocene Yushe material suggests that the Pseudomeriones lineage involves increasing hypsodonty, with latest Miocene and Pliocene Pseudomeriones abbreviatus showing greater crown height than older late Miocene P. latidens.

Insectivoran mammals have been recovered by Sino-American field teams from various localities in each formation of the Yuncu and Tancun subbasins. They were an important component of late Miocene through Pliocene faunas of North China. One hedgehog has been found in late Pliocene and Pleistocene localities. Moles, however, are diverse and occur throughout the Miocene and Pliocene section, with one early Pliocene record of the water mole Desmana. The Yushe collection includes the Pliocene talpine Scaptochirus, which is at present the oldest fossil of this genus. Shrews are also diverse, including multiple representatives of the tribes Soricini, Nectogalini, and Beremendiini. Presence of a blarinine suggests immigration of this element from North America by 6 Ma, and morphological similarity with beremendiines suggests that recognition of these groups should be reviewed. The early Pleistocene Haiyan Formation has yielded only Sorex, and to date only Crocidura has emerged from the Pleistocene loess. Declining insectivoran diversity corresponds with a hypothetical decline in mean annual temperature. The insectivoran component of Yushe shows affinity with fossil and living faunas of North China, and a majority of elements are shared broadly across Eurasia. Two taxa at least (Yunoscaptor and Soriculus) also occur in South China, indicating former wide distribution of these genera, and suggesting southward retraction of their preferred paleohabitat from Shanxi Province since the Pliocene.

Surface finds of small mammal fossils tend to be large body-size species; small species are retrieved more readily by applying special collecting techniques. The bias against small fossil recovery from Yushe Basin was greatly diminished by screen washing, beginning in 1987. Prior to that time, the historical monographic study by Teilhard de Chardin on the rodents of Yushe Basin focused on relatively large body-size species, especially beavers and zokorsZokor . Two other large kinds of rodents, bamboo rats and porcupines, were known to Teilhard and are reviewed here. Of these, the bamboo rats include Brachyrhizomys shansius Teilhard de Chardin, 1942 named for fossils from the Pliocene of Yushe, and a smaller late Miocene bamboo rat recovered by the Sino-American collaborative field team in 1991. This species is the oldest rhizomyine in North China, and the oldest species assignable to the extant Rhizomys group. Specimens representing the Old World porcupine Hystrix have stratigraphic importance, with a higher crowned species replacing Hystrix gansuensis by the early Pleistocene.

Targeted prospecting and screening for microfossils has revealed rich small mammal assemblages at many stratigraphic levels from late Miocene through Pliocene to early Pleistocene formations of the Yushe Basin. The recovered rodents, lagomorphs, bats, and insectivorans include species of small body size not previously known from Yushe. These assemblages represent North ChinaNorth China small mammal communities from about 6.5 to 2 Ma and may be used to characterize four land mammal stage/ages: Baodean, Gaozhuangian, MazegouanMazegouan (Age) , and Nihewanian. The fossil succession establishes diversity and stability in Pliocene small mammal faunas for Yushe Basin before significant turnover at the beginning of the Pleistocene. The Yushe Basin habitat was relatively moist, probably without strong annual temperature extremes, supporting high species diversity.

An extra affiliation is added for the authors of the article by Wu et al. [(2017), Acta Cryst. F73, 393-397].

We review and expand the systematics and biostratigraphic record of murine rodents in Yushe Basin. Several new taxa were established for the Pliocene fossil record of North ChinaNorth China following our initial field work of the 1980s. The rodent collection was expanded and developed by complementary field work in 1991, and subsequent study. Herein we present a new Late Miocene genus and review all occurrences of Yushe Murinae. Relatively primitive taxa characterize the Late Miocene of Yushe, and these appear to be related to early lineages that diversified in the Indian Subcontinent. The interval of about 6–5 Ma in Yushe records several murines that occur at Ertemte, Inner Mongolia: Karnimatoides hipparionus, Apodemus orientalis, and Micromys chalceus. Chardinomys is an additional genus that distinguishes Yushe microfaunas from other Asian assemblages, and the common C. yusheensis ranges from latest Miocene through early Pliocene. With Chardinomys, the genus Huaxiamys characterizes Late Neogene Yushe murine assemblages. The Pliocene of Yushe Basin records successive species of Chardinomys, Micromys, Huaxiamys, and Apodemus. Derived species of Chardinomys, Micromys, and Apodemus persist into the Pleistocene.

Fossil hamsters are a minor but constant microfauna component in the succession of Yushe Basin deposits. They indicate considerable hamster diversity for North ChinaNorth China during the late Neogene, with at least six genera and eight species recorded from late Miocene to early Pleistocene assemblages. Neocricetodon is a long-ranging late Neogene hamster, with closely related species widespread throughout Europe and Asia. Yushe Basin famously produced the type material of Neocricetodon grangeri, which we show to come from the late Miocene Mahui Formation south of the town of Yushe. Neocricetodon grangeri ranges from late Miocene (6.3 Ma) to early Pliocene (4.7 Ma) deposits. Later long-ranging Pliocene hamster lineages are Allocricetus and Cricetinus, for each of which we define a new species. Joining the latter two genera during the Late Pliocene, the living Cricetulus brings to three the number of coeval hamster genera. Finally, by the early Pleistocene, the modern genus Phodopus appears and coexists with Cricetulus in Yushe Basin.

The myelin sheath, which envelops axons in the vertebrate central nervous system, is crucial for the rapid conduction of action potentials. Myelin-gene regulatory factor (MRF) is a recently identified transcription factor that is required for myelin-sheath formation. Loss of MRF leads to demyelinating diseases and motor learning deficiency. MRF is a membrane-bound transcription factor that undergoes autocleavage from the endoplasmic reticulum membrane. The N-terminus of MRF contains a DNA-binding domain (DBD) that functions as a homotrimer. In this study, the MRF DBD was cloned, purified and crystallized in order to understand the molecular mechanism that regulates the transcription of myelin genes. Selenomethionine was subsequently introduced into the crystals to obtain the phases for the MRF DBD structure. The native and selenomethionine-labelled crystals exhibited diffraction to 2.50 and 2.51 Å resolution, respectively. The crystals belonged to space group P 321 and the selenomethionine-labelled crystals had unit-cell parameters a = 104.0, b = 104.0, c = 46.7 Å, α = 90, β = 90, γ = 120°. The calculated Matthews coefficient was 3.04 Å 3 Da −1 and the solvent content was 59.5%, indicating the presence of one MRF DBD molecule in the asymmetric unit.

Yushe Basin is an intermontane basin at the eastern edge of the Loess Plateau in northern China. Its fluvial, lake and superposed loess deposits accumulated during the last 7 myr and contain many fossiliferous horizons. Small mammal fossils occur throughout, and some fossil horizons produce diverse assemblages that appear to faithfully represent the micromammal component of Yushe paleocommunities. Yushe Basin includes assemblages that represent the late Baodean age (latest Miocene) microfaunas of North ChinaNorth China , and document contrasting younger assemblages that characterize a distinct Pliocene Yushe chronofaunaChronofauna . Pliocene fossils represent two successive microfaunas that distinguish the Gaozhuangian and MazegouanMazegouan (Age) land mammal stage/ages. These are in turn distinct from the Pleistocene assemblages of Yushe that correlate with NiheNihe wan and later faunas. The Sino-American project, especially in the interval of 1987–1991, developed the small mammal biostratigraphyBiostratigraphic, biostratigraphy of the Yuncu subbasin of Yushe Basin. Small mammal fossils occur in every Yuncu formation, from the Baodean age Mahui Formation, through the Pliocene GaozhuangGaozhuang (village) and Mazegou formations, to the early Pleistocene Haiyan Formation. Important elements of later Pleistocene faunas occur in overlying loess. Field teams collected specimens exposed on eroded surfaces and followed indications of small mammal concentrations to excavate bulk samples and process them for fossils by wet screening. Wet screening revealed a rich component of micromammal diversity to complement the wealth of larger species that previously had been known as surface finds.

Absent from Miocene and Pleistocene assemblages of Yushe Basin, prometheomyine Arvicolinae are a common and characteristic element of Pliocene faunas. Two time-successive species of the genus Germanomys are well represented in the Gaozhuang and Mazegou formations and serve as index fossils for Gaozhuangian and MazegouanMazegouan (Age) faunas. The genus Germanomys is well known in the Pliocene of Europe, but the oldest Yushe Germanomys (at about 4.7 Ma) is appreciably older than the European records, yet relatively derived in stage of evolutionStage of evolution of crown height and sinuousity of the base of the enamel on molars. The younger Germanomys species is late Pliocene in age, higher crowned, and shows a more derived sinuous line. In addition to the Germanomys lineage that is well represented in the Yushe Pliocene sequence, we find evidence of the distinct genus Stachomys and perhaps another prometheomyine in Yushe Basin.

Of historical collections of small mammals recovered from the Yushe Basin, fossil lagomorphs comprise a significant proportion because they are relatively large fossils and dentaries with teeth occur on the surfaces of exposures. Key fossils recovered prior to 1940 from various parts of North ChinaNorth China , including the Yushe Basin, formed the basis for early systematic studies of both ochotonids and leporids. Several Yushe Basin specimens were important in that early phase of research, and continue to be important in current revisions of Lagomorpha. This systematic treatment of the Yushe Lagomorpha embraces collections made by modern teams and classical collections of the Tianjin Natural History Museum, the American Museum of Natural HistoryAmerican Museum of Natural History (AMNH) , and the Institute of Vertebrate Paleontology and Paleoanthropology. For Yushe our study recognizes an array of Ochotona (pikas) and species of the larger genus Ochotonoides . Leporids are diverse for the late Neogene deposits of Yushe Basin, and included the genera Alilepus, Hypolagus, Trischizolagus Trischizolagus , and Sericolagus Sericolagus ; overlying Pleistocene loess yielded Lepus as well. These findings, including four new species, are important for lagomorph systematics, but also for the chronology of lagomorph evolution, because the Yushe sequence improves understanding of the relative ages of isolated Late Neogene deposits in China, and more broadly across Asia.

周氏似日本睡鼠Gliruloides zhoui是发现于新疆准噶尔盆地北缘晚渐新世铁尔斯哈巴合哺乳动物组合Ⅰ带的一个化石新属种.新属似日本睡鼠Gliruloides的属征为:中等大小;颊齿咀嚼面凹;上、下颊齿通常具9条主要横脊,有时具次级附脊;上颊齿的前边附脊和后边附脊以及下颊齿的下前边附脊和下后边附脊都很发育,几乎占据了其所在齿谷的整个长度.上颊齿的横脊唇端趋于游离.M1和M2具V形或窄U形三角座,内脊不完整或近于完整,前中央脊不与内脊相连.下颊齿的下内脊通常不连续;下臼齿的下前边脊在唇端稍向后弯,但不与原尖相连.p4,ml-m3,P4,M1-M3的齿根数分别为2,2,3,3.新属与Glirulus在形态上相似,但Glirulus的上颊齿的三角座均为宽U型,具有完整的内脊,前中央脊通常与内脊相交,横脊唇端通常不游离.新属与Vasseuromys属的最主要形态差异在于上颊齿具有很发育的前边附脊和后边附脊,而后者上颊齿的前边附脊和后边附脊通常缺失或很不发育.归入该属的种还有土耳其早中新世的Vasseuromys duplex和Vasseuromys aff.V.duplex.土耳其Thrace早渐新世的Glis guerbuezi很可能是Gliruloides和Glirulus的共同祖先类型.Gliruloides可能生活于温湿的生态环境.

宁夏同心丁家二沟哺乳动物群是中国中中新世早期最具代表性的地方动物群,但长期以来,对这一动物群产出层位的认识处于模糊和混乱的状态.本文通过对丁家二沟一带新生界地层的划分和对比,将出产丁家二沟动物群的彰恩堡组划分为下、中、上3个层位,其中下部和中部的层位分别产出两个时代不同的动物群:下部的印子岭动物群以Alloptox gobiensis-Protanancus tobieni-Caementodon tongxinensis-Turcocerus sp.1组合为代表,时代对应于欧洲陆相哺乳动物分期的MN5;中部的马二嘴子沟动物群则以Alloptox gobiensis-Platybelodon tongxinensis-Hispanotherium matritense-Turcocerus sp.2组合为代表,时代对应于欧洲陆相哺乳动物分期的MN6;而上部的地层则需要进一步研究划分.同时,丁家二沟地区彰恩堡组的下部层位的时代约为17～ 15Ma,跨越了中中新统的下界,可以考虑在这一地区重新建立中国陆相通古尔阶下界,使其与中中新统的下界相一致.此外,丁家二沟地区北部彰恩堡组与下伏清水营组成不整合接触,南部干河沟组中发育了生长断层,可能代表了这一地区对约20Ma和10Ma青藏高原两次强烈构造事件在东北部的远程响应.

Fossil gazelles have been widely distributed in Eurasia and Africa during the late Neogene. They are key elements of “Hipparion” faunas with prominent biochronologic and ecological significance. However, no pre-Baodean age gazelle previously reported from China. We describe here in detail materials found from the Bahe Formation, Shaanxi Province, which include by far the most complete skulls and postcranials. The first fossil gazelle skeleton is mounted based on the new findings. Morphology and measurements show the similarity with Gazella lydekkeri from Dhok Pathan Formation of middle Siwaliks, different from the most common species G. gaudryi, G. paotehensis, and G. dorcadoides from Baodean age and other gazelles from Europe. Ecomorphology and measurements of long bones indicate the Lantian species, Gazella cf. G. lydekkeri, is possibly a fast runner, adapted to an open environment in Bahean age. The open environment was also suggested by faunal composition, sedimentological analysis and isotope data.

Stable carbon and oxygen isotope ratios of 311 enamel samples from a diverse group of herbivorous mammals including Equidae, Rhinocerotidae, Bovidae, Rodentia and Ochotonidaewere were analyzed in order to reconstruct the Late Cenozoic history of vegetation and environmental change in the Yushe Basin in North China. The δ13C values of bulk and serial enamel samples from large mammals show a wide range of variation from −13.3‰ to 1.4‰, with a mean of −7.4‰±3.5‰ (n=294). This indicates that large herbivorous mammals in the area had a variety of diets since 6.5Ma, ranging from pure C3 to mixed C3–C4 and pure C4 diets. In contrast, the δ13C values of small mammals vary from −11.9‰ to −7.6‰, with a mean of −9.7±1.1‰ (n=17), indicating that rodents and ochotonids were feeding mostly on C3 plants. Variations in δ13C values within and between species reflect the variations in the habitat and the vegetation consumed by the animals. In general, horses had higher amounts of C4 grasses in their diets than other contemporary taxa such as bovids, rhinos, rodents and deer, suggesting that horses exploited more open habitats such as grasslands while deer, rhinos and rodents may have preferred more C3 vegetation, which is more indicative of forested environments. The carbon isotope data show that C4 grasses have been an important component of horses' diets and of local ecosystems since ~6.5Ma, confirming that the “late Miocene C4 expansion” occurred in North China as it did in Africa, Indian subcontinent and the Americas. This supports a global factor as a main driver of the late Miocene C4 expansion. The combined carbon and oxygen isotope data reveal major shifts in climate to drier and/or warmer conditions after ~5.8, ~4.1, ~3.3, and ~2.5Ma, and significant shifts to relatively wetter and/or cooler conditions after ~6.4, ~5, ~3.5Ma. The shifts to drier and/or warmer climate after ~5.8Ma and ~2.5Ma coincide with two major fauna turnover events. Intra-tooth δ13C and δ18O values are negatively correlated within individual modern teeth and some fossil teeth, displaying the characteristic pattern of the summer monsoon regime and confirming a strong monsoon influence in the area since at least the early Pliocene. The data also suggest that the C4 abundance in the area has fluctuated over the past 6.5Ma in response to changes in climate, with more C4 grasses during warmer and/or drier periods and a reduced C4 component at cooler and/or wetter times.

Mammalian bipedalism has long been thought to have arisen in response to arid and open environments. Here, we tested whether bipedalism coevolved with environmental changes using molecular and paleontological data from the rodent superfamily Dipodoidea and statistical methods for reconstructing ancestral characteristics and past climates. Our results show that the post-Late Miocene aridification exerted selective pressures on tooth shape, but not on leg length of bipedal jerboas. Cheek tooth crown height has increased since the Late Miocene, but the hind limb/head-body length ratios remained stable and high despite the environmental change from humid and forested to arid and open conditions, rather than increasing from low to high as predicted by the arid-bipedalism hypothesis. The decoupling of locomotor and dental character evolution indicates that bipedalism evolved under selective pressure different from that of dental hypsodonty in jerboas. We reconstructed the habitats of early jerboas using floral and faunal data, and the results show that the environments in which bipedalism evolved were forested. Our results suggest that bipedalism evolved as an adaptation to humid woodlands or forests for vertical jumping. Running at high speeds is likely a by-product of selection for jumping, which became advantageous in open environments later on.

The proliferation of vascular smooth muscle cells may perform a crucial role in the pathogenesis of diabetic vascular disease. AMPK additionally exerts several salutary effects on vascular function and improves vascular abnormalities. The current study sought to determine whether sodium tanshinone IIA silate (STS) has an inhibitory effect on vascular smooth muscle cell (VSMC) proliferation and migration under high glucose conditions mimicking diabetes without dyslipidemia, and establish the underlying mechanism. In this study, STS promoted the phosphorylation of AMP-activated protein kinase (AMPK) at T172 in VSMCs. VSMC proliferation was enhanced under high glucose (25 mM glucose, HG) versus normal glucose conditions (5.5 mM glucose, NG), and this increase was inhibited significantly by STS treatment. We utilized western blotting analysis to evaluate the effects of STS on cell-cycle regulatory proteins and found that STS increased the expression of p53 and the Cdk inhibitor, p21, subsequent decreased the expression of cell cycle-associated protein, cyclin D1. We further observed that STS arrested cell cycle progression at the G0/G1 phase. Additionally, expression and enzymatic activity of MMP-2, translocation of NF-κB, as well as VSMC migration were suppressed in the presence of STS. Notably, Compound C (CC), a specific inhibitor of AMPK, as well as AMPK siRNA blocked STS-mediated inhibition of VSMC proliferation and migration. We further evaluated its potential for activating AMPK in aortas in animal models of type 2 diabetes and found that Oral administration of STS for 10 days resulted in activation of AMPK in aortas from ob/ob or db/db mice. In conclusion, STS inhibits high glucose-induced VSMC proliferation and migration, possibly through AMPK activation. The growth suppression effect may be attributable to activation of AMPK-p53-p21 signaling, and the inhibitory effect on migration to the AMPK/NF-κB signaling axis.