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Discriminating the provenance of fine-grained sediments is crucial for reconstructing paleogeography, sedimentary processes, and paleoclimate. In this paper, we investigate the South Bohai Coast to better understand source-to-sink systems in East Asia. This region is influenced by both distant sources such as the large-scale Yellow River and small local river sources flowing from the Luzhong Mountain area. Two Holocene sedimentary cores, dated using optically stimulated luminescence (OSL) and accelerator mass spectrometry (AMS) 14C chronology, were used to investigate the provenance of the fine-grained sediments over the last 7 kyrs. Clay mineralogy and relevant non-linear modeling were employed for provenance discrimination. The results show that the fine-grained sediments along the South Bohai Coast were mainly derived from the Yellow River during the periods of 7.0–5.4 ka and 4.5–2.6 ka, respectively, while the input from the Luzhong Mountain-derived rivers was greater during 5.4–4.5 ka and 2.6–0.2 ka, respectively. Fluvial activities and marine-terrestrial interaction driven by climate factors such as East Asian winter monsoon, temperature, and precipitation in river basins, dominantly influenced the provenance of fine-grained sediments from 7.0 to 2.6 ka. Anthropogenic impact on provenance increased after 2.6 ka. The chronology of the two cores showed extremely rapid sedimentation rate transitions at 5.2 ka and 1.5 ka, respectively, very likely attributed to anthropogenic-induced rapid progradation. Our study provides a model for better understanding the paleoenvironmental and paleogeographic evolution of a coastal area where multiple sources exist. • Anthropogenically high sedimentation rate in the South Bohai Coast in late Holocene. • Provenance discrimination of the fine-grained sediments in the South Bohai Coast since the mid-Holocene. • The major source of the fine-grained sediments in the South Bohai Coast changed episodically. [ABSTRACT FROM AUTHOR]

In this paper, stable isotope (δ 13C, δ 18O) analyses of five equid species from the Linxia Basin, northwestern China, were conducted to investigate dietary niche turnover during a critical Pliocene-Pleistocene phase in the evolution of Old World Equidae. In the Early Pliocene Shilidun fauna, Proboscidipparion pater is inferred to have mainly fed on C 3 grasses in open grasslands as indicated by their relatively high δ 13C values (−9.1 ± 0.4‰, five teeth, n = 61), whereas Cremohipparion licenti and Sivalhippus platyodus were possibly mixed feeders inhabiting woodlands and grasslands because of their comparatively low δ 13C values (−10.8 ± 0.6‰, seven teeth, n = 36; −10.6 ± 0.6‰, nine teeth, n = 35). Inhabiting the same environments, both C. licenti and S. platyodus went extinct, possibly, because climatic changes led to a decline in woodlands resulting in greater competition. In the Early Pleistocene Longdan fauna, Proboscidipparion sinense had higher δ 13C values (−9.1 ± 0.5‰, four teeth, n = 23) than coexisting Equus eisenmannae (−10.2 ± 0.5‰, eight teeth, n = 57), implying that P. sinense had a stronger grazing preference compared to E. eisenmannae. Ecomorphological analyses (body size, tooth crown height, and enamel surface complexity) reveal that P. pater and P. sinense had dental characteristics consistent with a strong grazing preference. Therefore, P. pater might have been preadapted to open grasslands during the warm and humid Early Pliocene, which helped its descendent P. sinense persist into the Pleistocene. The results of this study reveal distinct dietary niches for these equids for the first time and shed light on some aspects of the evolutionary history of Equidae in East Asia. • Dietary niche partitioning of five fossil equids were reconstructed through stable isotopes in East Asia for the first time. • Preadaption to open grasslands of Proboscidipparion pater during the Pliocene helped this genus persist into Pleistocene. • Cremohipparion licenti and Sivalhippus platyodus went extinct due to interspecific competition on habitats in Pliocene. • Early Pleistocene hipparion Proboscidipparion sinense occupied more open environments than coexisting Equus eisenmannae. [ABSTRACT FROM AUTHOR]

The 8.2 ka BP cooling event is the most prominent and abrupt climate event in the Holocene at mid-to-high latitudes in the Northern Hemisphere. In this paper, we conduct model simulations of vegetation responses to the 8.2 ka BP event over East Asia, and compare them with pollen-based vegetation records. Our results reveal that all major Plant Functional Types responded to the climate changes, but the magnitude, timing, and impact of their responses varied. In addition, it was found that after the 8.2 ka BP climate event the vegetation did not always recover to the state simulated before the perturbation, suggesting that different vegetation compositions may occur under similar climate conditions. Changes in temperature exerted a major influence on the vegetation dynamics in the most high latitude regions, and changes in both temperature and precipitation were responsible for the vegetation changes at mid-to-high-latitudes. Compared with pollen-based vegetation reconstructions, our model simulations generally capture the main features of vegetation responses to the 8.2 ka BP event. Notably, only a relatively small proportion of taxa were climatically sensitive during the 8.2 ka BP cooling in pollen records. Only one high-resolution pollen record indicated that the vegetation did not recover to the pre-perturbed state, showing a different vegetation composition after the 8.2 ka BP event similar to our simulations. Such different vegetation compositions could be a long-lasting effect of abrupt climate changes on vegetation through eco-physiological and ecosystem demographic processes, e.g., plant competition. Moreover, our model simulations suggest a more pronounced vegetation responses to the severe cooling in the north and weaker responses to less cooling in the south. Since significant vegetation responses during this event were only seen in few records, more high-resolution pollen records and simulations in terms of vegetation responses to different abrupt climate changes are needed in future. • All dominant PFTs over East Asia responded to the 8.2 ka BP event, but their magnitude, timing, and impact factors vary. • Temperature domain northern vegetation dynamics; temperature and precipitation drive vegetation changes at mid-latitudes. • Simulations agree with pollen-based vegetation responses, but long-lasting effects can only be seen in few pollen records. [ABSTRACT FROM AUTHOR]

The spatio-temporal vegetation patterns of East Asia in the Eocene remain uncertain. In this present paper, we conduct numerical analyses of plant functional types (PFTs) for 80 Eocene floras, subdivided into three-time intervals: the early, middle, and late Eocene. Based on PFT diversity spectra, five groups are identified from cluster analysis and interpreted in terms of vegetation type. These PFT-based vegetation reconstructions suggest a northwestward retreat of dry shrub or open woodland from early to late Eocene times, coupled with the expansion of humid broadleaved forest from the southeast. This hydrological distribution is consistent with mammal distribution, lithological indicators and geochemical proxies. An overall vegetation pattern of largely east-west differentiation is detected and we note that no unequivocal tropical vegetation is observed in low-latitudes during the Eocene. Our results indicate that a monsoonal climate shaped the Eocene spatio-temporal evolution of vegetation in East Asia along with the global cooling, and rain-shadow effects by the central and southwestern China highland, as well as basin extensions in the Pacific coast in the east. • Eocene vegetational dynamics of East Asia are quantitatively reconstructed. • A west-east differentiation is suggested in Eocene East Asian vegetation pattern. • Climate and paleo-landform factors contribute the vegetational dynamics. [ABSTRACT FROM AUTHOR]

Extinct hyenas of the genus Crocuta were typical representatives of the Late Pleistocene mammoth fauna of Eurasia. The geographical distribution of these animals was vast, stretching from the British Isles to the Pacific coast. In this paper, we studied the tooth microwear of Crocuta spelaea from the Prolom 2 grotto in Crimea and the Bukhtarminskaya Cave in eastern Kazakhstan, and C. ultima ussurica from the Geographical Society Cave in the Russian Far East, to provide a comparative analysis of the feeding habits of these two species and to test for ecological differences. We also tested for ontogenic differences in diet through a comparison of juvenile and adult individuals. Our findings show that the microwear patterns of these Late Pleistocene hyenas resemble those of extant spotted hyenas (C. crocuta) but differ from those of extant stripped (Hyaena hyaena) and brown hyenas (Parahyaena brunnea). However, we noted that the number of scratches in the C. ultima ussurica specimens exceeded the variability observed in extant spotted hyenas and instead more closely resembled the microwear signal of typical predators (e.g., lions). Adults and juveniles exhibited similar microwear patterns in terms of the quantity of pits and scratches; however, most juveniles lacked cross scratches, as also observed in most individuals from Prolom 2. This pattern could be related to a higher proportion of meat in the diet of juveniles, without excluding the consumption of bones. Our tooth microwear analysis improves the knowledge of the paleobiology of extinct representatives of the genus Crocuta. • First tooth enamel microwear study to evaluate the paleodiet of the cave hyena • Similar diets in the three populations of hyenas from Eastern Europe and Eastern Asia • Overall similarity to the diet known for the extant spotted hyena • Ontogenic differences between the adults and the juveniles • Microwear patterns show relevant inter-specific and intra-specific differences. [ABSTRACT FROM AUTHOR]

Yue et al. (2021) have proposed a model of two Upper Palaeolithic industries in Northeast China called the "Initial Microblade Industry" and the "Northern Microblade Industry", with the latter originating from the former, and its spread to the neighbouring regions of Northeast Asia. We have found several inconsistencies in their factual data and methodology, and therefore the conclusions reached by Yue et al. (2021) cannot be accepted at face value. Using the most reliable evidence, the oldest true microblade assemblages are known from the Korean Peninsula. We suggest that this region is the more probable centre of diffusion of microblade technology in mainland Northeast Asia, including China and the Russian Far East. • Yue et al. (2021) published paper on microblades in Northeast China. • They have several inconsistencies in factual data and methodology. • We address the most debatable issues related to Yue et al. (2021). • The earliest true microblades originated in Korea and not in Northeast China. [ABSTRACT FROM AUTHOR]