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The unique co‐occurrence of thyriothecia belonging to three fossil genera of epiphyllous fungi, Stomiopeltites Alvin & Muir (Micropeltidaceae), Callimothallus Dilcher, and Trichothyrites Rosendahl (Microthyriaceae), are reported on the leaves of the same host plant, Cunninghamia shangcunica Kodrul, Gordenko & Sokolova from the Oligocene Shangcun Formation of the Maoming Basin, South China. In China, Stomiopeltites is identified for the first time, Callimothallus is known from the Oligocene and Miocene of Guangxi and Zhejiang provinces, and Trichothyrites previously has been found only in the Eocene palynological assemblages of the Maoming Basin. The presence of abundant and diverse epiphyllous micromycetes, together with the taxonomic composition of the Shangcun megaflora and pollen assemblage, as well as quantitative climatic estimates obtained using Climate Leaf Analysis Multivariate Program, confirm the existence of a warm and humid climate in this region during the late early Oligocene. The geographic and stratigraphic distributions, comparisons with extant analogues, as well as ecological and paleoclimatic implications of the fossil fungi are discussed. [ABSTRACT FROM AUTHOR]

Premise: Microclimatic differences between the periphery and the interior of tree crowns result in a variety of adaptive leaf macromorphological and anatomical features. Our research was designed to reveal criteria for sun/shade leaf identification in two species of evergreen oaks, applicable to both modern and fossil leaves. We compared our results with those in other species similarly studied. Methods: For both Quercus bambusifolia and Q. myrsinifolia (section Cyclobalanopsis), leaves from single mature trees with well‐developed crowns were collected in the South China Botanical Garden, Guangzhou, China. We focus on leaf characters often preserved in fossil material. SVGm software was used for macromorphological measurement. Quantitative analyses were performed and box plots generated using R software with IDE Rstudio. Leaf cuticles were prepared using traditional botanical techniques. Results: Principal characters for distinguishing shade and sun leaves in the studied oaks were identified as leaf lamina length to width ratio (L/W), and the degree of development of venation networks. For Q. myrsinifolia, shade and sun leaves differ in tooth morphology and the ratio of toothed lamina length to overall lamina length. The main epidermal characters are ordinary cell size and anticlinal wall outlines. For both species, plasticity within shade leaves exceeds that of sun leaves. Conclusions: Morphological responses to sun and shade in the examined oaks are similar to those in other plant genera, pointing to useful generalizations for recognizing common foliar polymorphisms that must be taken into account when determining the taxonomic position of both modern and fossil plants. [ABSTRACT FROM AUTHOR]

The study of fossil plant–biotic (mainly arthropod) interactions offers an opportunity to understand the evolutionary process in palaeoecosystems and their response to climate fluctuation. Despite the importance of such investigations, not much is known about plant–arthropod associations from the Cenozoic floras of Asia. Exceptionally diverse Eocene floras from adjacent Maoming and Changchang sedimentary basins of southern China provide valuable insights into low-latitude palaeoecosystems. These floras indicate different intensities of plant–arthropod interactions and probably viral, bacterial or fungal infection. Two upper Eocene floras from the Maoming Basin are markedly distinct from two approximately contemporaneous middle Eocene floras of the Changchang and Maoming basins in exhibiting much more abundant and diverse plant damage types (DTs). For equivalent comparisons we focus on well-sampled fossil leaves of Liquidambar L. (Altingiaceae) present and relatively abundant in both basins. L. maomingensis and Liquidambar sp. 1 from both upper Eocene Maoming floras exhibit mainly external foliage feeding. In contrast, almost only galling occurs on Liquidambar sp. 2 leaves from the middle Eocene Changchang flora. The differences in the diversity and frequency of DTs in the studied palaeofloras could have been affected by a progressive warming and increase in climate seasonality over the middle–late Eocene interval as well as by habitat conditions and plant successional status. We hypothesize that L. maomingensis and Liquidambar sp. 1 from the Maoming Basin inhabited the early successional riparian forests on an alluvial plain, whereas Liquidambar sp. 2 from the Changchang Basin was a component of more mature plant communities. [ABSTRACT FROM AUTHOR]

The Qaidam Basin in the northern Tibetan Plateau is currently arid, but may have had a semi-humid to semi-arid climate in Miocene times, as suggested by pollen and isotopic data; however, the lack of macroscopic fossils hinders more precise paleoclimatic calibration. In this paper, we report fossil leaves with insect damage from a late Miocene layer (HT-5) in the Huaitoutala section dated ∼11.4 Ma, and compare them with records from a middle Miocene layer (HT-1) dated ∼12.7 Ma. Results show that damage diversity dropped from 36 types in HT-1 to 24 types in HT-5, suggesting a fall in mean annual temperature. Damage frequency decreased from 70 % in HT-1 to 32 % in HT-5, pointing to a drop in the coldest month temperature. Moreover, a slight fall in the diversity of mining damage, from 5 types in HT-1 to 4 types in HT-5, suggests a shift towards a slightly more arid climate from the middle to late Miocene. The flora from HT-5 is composed mainly of Betulaceae, Populus , Ulmus , and shrubs. Based on the distribution of these taxa in modern vegetation, the climate was probably semi-humid, not entirely arid during the late Miocene. These results are corroborated by fossil mammal data from the same section. Therefore, despite a cooling and drying trend from the middle to late Miocene, the climate of the Qaidam Basin was not as extremely arid as today. • New discovery of the Miocene plant-insect interactions in the Tibetan Plateau; • The comparison of the insect damage data from the same site but different layers; • The Miocene cooling and drying climate trend based on the plant-insect indicators. [ABSTRACT FROM AUTHOR]

Abstract A new species of the genus Cunninghamia (Cupressaceae s.l.) is reported from the Lower Oligocene Shangcun Formation of the Maoming Basin, Guangdong Province, South China based on compressions/impressions of leafy shoots and an isolated leaf. Cunninghamia shangcunica sp. nov. possesses helically arranged and radially spread polymorphic leaves. Most Cretaceous cunninghamioid species exhibits a similar phyllotaxis with this new species, and it can be regarded as a primitive character. In the Miocene species, terminal shoots with a bilateral (pectinate) arrangement of leaves predominated. The new species is similar to the extant species C. konishii in shoot and leaf morphology, and to С. lanceolata in the characters of the epidermis. The new Oligocene species increases the known diversity of the genus Cunninghamia in its refugial region and contributes to a greater understanding of the specific variability and ecology of this conifer. A diverse population of epiphyllous fungi on the leaves of the new species are recorded and figured. Highlights • Cunninghamia foliage with well-preserved cuticle from the Oligocene of South China. • New species with helically arranged and radially spread polymorphic leaves. • The earliest fossil record of Cunninghamia in China. [ABSTRACT FROM AUTHOR]

Plant–arthropod interaction offers insight into the evolution of terrestrial ecosystems in the geological past. In this study, leaf fossils with arthropod traces, collected from the Miocene Huaitoutala flora, Qaidam Basin, northern Tibetan Plateau, were studied to provide direct evidence of plant–arthropod interactions on the Tibetan Plateau. The results show a total of 36 damage types belonging to eight different functional feeding groups, classified on 303 out of 433 leaf specimens with a damage frequency of 70%. Compared to other Miocene fossil floras worldwide, the Huaitoutala flora represents a relatively high frequency and diversity of damage. It indicates that, apart from climatic factors, the influence of local niche and biotic factors might have contributed to the intensive plant–arthropod interactions observed at that time, suggesting that the Miocene ecosystem hereof was not as barren as previously thought. • Miocene plant–arthropod interactions are reported from Huaitoutala, Qaidam Basin. • Relatively high damaged frequency in the Huaitoutala flora is found. • Both biotic and abiotic factors contribute to the high damaged frequency. [ABSTRACT FROM AUTHOR]